Acidi & basi

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Acids & bases

Acids and bases are important groups within the classification of chemical substances, since they are widely used in any type of laboratory or industrial process due to their multiple applications. (e.g digestion of samples in an analytical laboratory using HNO3, catalyst in chemical reactions, acidic hydrolysis, pH adjustments, manufacturing of fertilizers, synthesis of nylon, etc).

Acids and bases are also common substances that exist everywhere, found in many everyday items, like in food, medicines, or cleaning agents, e.g., vinegar, lemon juice, baking soda, aspirin, soaps, etc.

In chemistry, acids and bases have been defined differently by three sets of theories:

  • The Arrhenius definition which is based on the idea that acids are substances that ionize (dissociate) in an aqueous solution to release hydrogen ions or protons (H+) while bases release hydroxide ions (OH) in solution. This led to Arrhenius receiving the Nobel Prize in Chemistry in 1903.
  • The Brønsted-Lowry definition defines acids as substances that donate protons (H+) whereas bases are substances that accept protons. The advantage of this definition is that it is not limited to aqueous solutions. Brønsted-Lowry acids and bases always occur in pairs called conjugate acid-base pairs. The pairs are related through the transfer of a proton.
  • The Lewis theory of acids and bases states that acids are electron-pair acceptors (to form a covalent bond) while bases are electron-pair donors (to form a covalent bond). This definition is the most inclusive and encompasses species not included in the Brønsted-Lowry definition.


Brief summary - the three concepts of acid and bases:

Arrhenius – the first modern approach
Acid: produces H+ (protons) in aqueous solution
Base: produces OH- (hydroxide ions) in aqueous solution

Brønsted-Lowry – the most generally accepted
Acid: proton donor
Base: proton acceptor

Lewis – the most inclusive
Acid: electron-pair acceptor (to form a covalent bond)
Base: electron-pair donor (to form a covalent bond)

Acids and bases combine or neutralize each other by acid-base reactions to form salts (see also more information on our salts & minerals page).

pH
The hydrogen ion concentration, [H+], is a measure of both Arrhenius and Brønsted-Lowry defined acids, a measure of the acidity or basicity (alkalinity) of a substance or solution. This is generally expressed as pH. The pH of a solution equals the negative of the logarithm to the base 10 of its hydrogen ion concentration:

pH = -log [H+] = log 1/[H+]

The pH offers a convenient mechanism of expressing a wide range of [H+] in small positive numbers. The letter, p, is used to denote the negative logarithm to the base of 10.

Likewise, the hydroxide ion concentration may be expressed as pOH:

pOH = -log [OH-]

The pH scale from 0 to 14 covers usually all the hydrogen ion concentrations found in diluted aqueous solutions and biological systems. Pure water has a pH of 7 at 25 °C (as pH value depends on temperature), which is considered to be neutral, because the concentration of hydrogen ions [H+] equals the concentration of hydroxide ions [OH].

When pH < 7, the solution is acidic and when pH > 7, the solution is basic or alkaline. Because of the logarithmic function a change of one pH unit represents a tenfold difference in hydrogen ion concentration.

pH is the parameter most often measured in chemistry, particularly in analytical chemistry. It is also important in pool maintenance and water purification, agriculture, medicine, engineering, oceanography, biology, and other sciences.

Measurements of pH can be easily performed using a pH-meter, a color-changing indicator, or pH indicator papers.

Find also more information on:

Buffer

Dyes, Stains & Indicators


Acid/Base Strengths - Dissociation Constants – Ka, Kb and Kw

Strong acids and bases

Strong acids and bases are those that completely dissociate into their component ions in aqueous solution.

In water, one mole of a strong monoprotic acid HA dissolves yielding one mole of H+ (as hydronium ion H3O+) and one mole of the conjugate base, A. Essentially, none of the non-ionized acid HA remains, each of these essentially ionizes 100%.

Strong acid: HA + H2O → A-(aq) + H3O+(aq)
Strong base: BOH + H2O → B+(aq) + OH-(aq)

For simplicity, H3O+ can be written as H+, although this free H+ does not exist in aqueous solutions, since in all acid ionization reactions a proton is transferred to H2O to form hydronium ions, H3O+.

Strong acid: HA(aq) → A-(aq) + H+(aq)
Strong base: BOH(aq) → B+(aq) + OH-(aq)

Examples of strong acids and bases:

STRONG ACIDS FORMULA STRONG BASES FORMULA
Hydrobromic acid HBr Barium hydroxide Ba(OH)2
Hydrochloric acid HCl Calcium hydroxide Ca(OH)2
Hydriodic acid HI Lithium hydroxide LiOH
Nitric acid HNO3 Potassium hydroxide KOH
Perchloric acid HClO4 Sodium hydroxide NaOH
Sulfuric acid H2SO4 Strontium hydroxide Sr(OH)2



Weak acids and bases

Weak acids and bases are those that only partially dissociate in aqueous solution. At equilibrium, both the acid and the conjugate base are present in solution. The dissociation of an acid or a base is expressed by the following reaction:

Weak acid: HA(aq) ⇋ A-(aq) + H+(aq)
Weak base: BOH(aq) ⇋ B+(aq) + OH-(aq)

The acid dissociation constant, Ka, is a measure of the degree of dissociation of the acid.

Ka = [HA+] [A- ] / [HA] or
pKa = -log [HA+] [A- ] / [HA] = log [HA] / [HA+] [A- ]

where quantities in square brackets represent the concentrations of the species at equilibrium.

Stronger acids have a larger acid dissociation constant (Ka) and a smaller logarithmic constant (pKa = −log Ka) than weaker acids. The stronger an acid is, the more easily it loses a proton, H+.
Acids with a Ka value less than one, or consequently pKa greater than 0, are considered weak.
Ka or pKa can therefore be used to distinguish between strong acids and weak acids.

Strong acids: Ka > 1 or pKa < 0
Weak acids: Ka < 1 or pKa > 0

Similarly, a weak monovalent base, BOH, dissociates to give B+ and OH-.

The base dissociation constant, Kb, is a measure of the degree that the base dissociates.

Kb = [B+] [OH-] / [BOH]

Examples of weak acids and bases:

WEAK ACIDS FORMULA WEAK BASES FORMULA
Acetic acid CH3COOH Ammonia NH3
Carbonic acid H2CO3 Diethylamine (CH3CH2)2NH
Formic acid HCOOH Methylamine CH3NH2
Hydrocyanic acid HCN Sodium hydrogen carbonate NaHCO3
Hydrofluoric acid HF
Phosphoric acid H3PO4


The dissociation of water

Kw - The water ionization constant
Water partially dissociates into ions according to the equation:

H2O ⇋ H+ + OH-

The equilibrium constant K for this reaction can be written as follows:

K = [H+] [OH-] / [H2O]

When pure liquid water is in equilibrium with hydrogen and hydroxide ions at 25 °C, the concentrations of the hydrogen ion and the hydroxide ion are equal: [H+] = [OH] = 1.0 × 10−7 mol/L.
Thus, the number of dissociated water molecules is very small indeed, approximately 2 ppb. One can calculate [H2O] at 25 °C from the density of water at this temperature (0.997 g/mL):

[H2O] = mol/L = 1 mol/18.02 g x 0.997 g/mL X 1000 mL/L = 55.3 mol/L

With so few water molecules dissociated, the equilibrium of the autoionization reaction lies far to the left. Consequently, [H2O] is essentially unchanged by the autoionization reaction and can be treated as a constant. Incorporating this constant into the equilibrium expression allows us to rearrange the equation to define a new equilibrium constant.

K [H2O] = [H+] [OH-]

As K is a constant and [H2O] is a constant we can replace both with a new constant Kw called the ion-product constant of liquid water (also called the ionic product of water, water autoprotolysis constant, water (auto)ionization constant or water-dissociation equilibrium constant).

Kw = [H+] [OH-]

As in pure water, at 25 °C, the [H+] and [OH-] ion concentrations are 1.0 x 10-7 mol/L. The value of Kw at 25 °C is therefore 1.0 x 10-14.

Kw = (1.0 x 10-7) (1.0 x 10-7) = 1.0 x 10-14 (at 25 °C)

Although Kw is defined in terms of the dissociation of water, this equilibrium constant expression is equally valid for solutions of acids and bases dissolved in water. Regardless of the source of the H+ and OH- ions in water, the product of the concentrations of these ions at equilibrium at 25 °C is always 1.0 x 10-14.

Consequently if:

[H+] [OH-] = 10-14

And taking the negative log on both sides of the equation gives:

-log [H+] – log [OH-] = 14

As pH = −log [H+] and pOH = −log [OH]

then:

pH + pOH = 14

The sum of pH and pOH is always 14 for any aqueous solution at 25 °C.

Conjugate acid-base pairs
According to Brønsted-Lowry definition, any acid and base exists as conjugate acid-base pair. Every time an acid acts as a H+ donor, it forms a conjugate base. When a generic acid HA donates a H+ to water, one product of the reaction is the A- ion, which is a hydrogen-ion acceptor, or Brønsted base.

Relationship between Ka and Kb for conjugate acid-base pair:

HA ⇋ A- + H+
acid base

Ka = [H+] [A- ] / [HA]

Since A is a base, we can also write the reversible reaction for A acting as a base by accepting a proton from water:
A- + H2O ⇋ HA + OH-

Then:

Kb = [B+] [OH-] / [BOH]

If we multiply Ka for HA with the Kb for its conjugate base A-, that gives:

Ka x Kb = [H+] [A- ] / [HA] x [HA] [OH-]/[A-] = [H+] [OH-] = Kw

where Kw is the water dissociation constant. This relationship is very useful for relating Ka and Kb for a conjugate acid-base pair. We can also use the value of Kw at 25 °C to derive other handy equations:

Ka x Kb = Kw
Kw= 10-14 at 25 °C
Ka x Kb = 10-14

If we take the negative logarithm of both sides of the equation, we get:

pKa + pKb = 14

We can use these equations to determine Kb (or pKb) of a weak base given Ka of the conjugate acid. We can also calculate the Ka (or pKa) of a weak acid given Kb of the conjugate base.

Two key factors that contribute to the ease of deprotonation are the polarity of the H-A bond and the size of atom A, which determines the strength of the H-A bond. Acid strengths also depend on the stability of the conjugate base.

A conjugate acid is defined as the acid formed when a base gains a proton. Similarly, a conjugate base is formed when an acid loses a proton. For example, with HCO3-/CO32- conjugate acid/base pair, the CO32- is the conjugate base and HCO3- is the conjugate acid.
By adding the reactions of the conjugate acid and conjugate base with water, the net reaction is simply the dissociation of water. Thus, if you know the dissociation constant for one, the other can be determined:

Ka x Kb = Kw = 10-14

Thus, Ka and Kb are inversely related. In other words, if Ka is large (the acid is strong), then Kb (base is weak) will be small and vice versa. From this relationship, one can see that when a conjugate acid/base pair form from a weak acid, the conjugate base is stronger than the acid.

ACID FORMULA Ka pKa CONJUGATED BASE FORMULA Kb pKb
Perchloric acid HClO4 1010 -10 Perchlorate ClO4- 10-24 24
Hydriodic acid HI 1010 -10 Iodide I- 10-24 24
Hydrobromic acid HBr 109 -9 Bromide Br- 10-23 23
Hydrochloric acid HCl 106 -6 Chloride Cl- 10-20 20
Sulfuric acid (1) H2SO4 103 -3 Hydrogen sulfate HSO4- 10-17 17
Nitric acid HNO3 24 -1.4 Nitrate NO3- 4.2x10-16 15.4
Phosphoric acid (1) H3PO4 7.5x10-3 2.1 Dihydrogen phosphate H2PO4- 1.3x10-12 11.9
Hydrofluoric acid HF 7.2×10−4 3.1 Fluoride F- 1.4x10-11 10.9
Formic acid HCOOH 1.8x10-4 3.7 Formate HCOO- 5.6x10-11 10.3
Acetic acid CH3COOH 1.8×10−5 4.8 Acetate CH3COO- 5.7x10-10 9.2
Carbonic acid (1) H2CO3 4.3x10-7 6.4 Hydrogen carbonate HCO3- 2.4x10-8 7.6
Hydrocyanic acid HCN 6.2x10-10 9.2 Cyanide CN- 1.8x10-5 4.8

(1) First dissociation

BASE FORMULA Kb pKb CONJUGATED ACID FORMULA Ka pKa
Lithium hydroxide LiOH ~ 102 to 103 -2 to -3
Potassium hydroxide KOH ~ 102 to 103 -2 to -3
Sodium hydroxide NaOH ~ 102 to 103 -2 to -3
Strontium hydroxide Sr(OH)2 ~ 102 to 103 -2 to -3
Barium hydroxide Ba(OH)2 ~ 0.01 – 0.1 1-2
Calcium hydroxide Ca(OH)2 ~ 0.01 – 0.1 1-2
Ammonia NH3 1.8×10−5 4.75 Ammonium NH4+ 5.6x10-10 9.25
Diethylamine (CH3CH2)2NH 6.9x10-4 3.16 Diethylammonium (CH3CH2)2NH2+ 1.4×10-11
Methylamine CH3NH2 4.6×10−4 3.34 Methylammonium CH3NH3+ 2.2×10-11 10.66
Sodium hydrogen carbonate NaHCO3 5.6x10-11 10.25 Carbonic acid H2CO3 4.3x10-7 6.4



Polyprotic acids
Acids can donate one, two or more protons (H+). Typical examples are:

MONOPROTIC ACID (HA) DIPROTIC ACID (H2A) TRIPROTIC ACID (H3A)
Hydrochloric acid HCl Carbonic acid H2CO3 Phosphoric acid H3PO4
Nitric acid HNO3 Sulfuric acid H2SO4 Boric acid H3BO3
Hydriodic acid HI Sulfurous acid H2SO3 Citric acid C₆H₈O₇
Acetic acid CH3COOH Hydrogen sulfide H2S Arsenic acid H3AsO4
Hydrofluoric acid HF Oxalic acid H2C2O4
Formic acid HCOOH Chromic acid H2CrO4


A monoprotic acid is characterized by a single acidity constant K1 (= Ka), a diprotic acid by two acidity constants (K1, K2), and a triprotic acid by three acidity constants (K1, K2, K3):

1st dissociation step: H3A = H+ + H2A- (K1)
2nd dissociation step: H2A- = H+ + HA2- (K2)
3rd dissociation step: HA2- = H+ + A3- (K3)

This can be extended to any N-protic acid with N dissociation steps.

Protons are released sequentially one after the other, with the first proton being the fastest and most easily lost, then the second, and then the third (which is most strongly bound). This yields the following ranking of acidity constants of a polyprotic acid:

K1 > K2 > K3 or pK1 < pK2 < pK3

For example, phosphoric acid has pK1 = 2.147, pK2 = 7.207, and pK3 = 12.346.

Amphoteric substances
An amphoteric compound is a molecule or ion that can react both as an acid and as a base. One type of amphoteric species are amphiprotic molecules, which can either donate or accept a proton (H+). This is what "amphoteric" means in Brønsted–Lowry acid–base theory. Examples include amino acids and proteins, which have amine and carboxylic acid groups, and self-ionizable compounds such as water. Metal oxides which react with both acids as well as bases to produce salts and water are known as amphoteric oxides. Many metals form amphoteric oxides or hydroxides. Ampholytes are amphoteric molecules that contain both acidic and basic groups and will exist mostly as zwitterions in a certain range of pH. A zwitterion is a molecule with functional groups, of which at least one has a positive and one has a negative electrical charge. The net charge of the entire molecule is zero.

Calculating pH
To calculate the pH of an aqueous solution you need to know the concentration of the hydronium
ion in moles per liter (molarity). The pH is then calculated using the expression:

pH = - log [H+].

Strong Acid:
From the definition of pH, and assuming that, because the acid is strong, the analytical concentration of the acid (Ca) is equal to the concentration of H+.

pH = -log Ca

Strong Base:
When the base is strong, the analytical concentration of the base (Cb) is equal to the concentration of OH. Since pH= 14 – pOH, becomes,

pH = 14 + log Cb

Weak acid:
Only some small fraction of molecules in solution dissociates to anion and proton, being x its concentration at equilibrium:

HA A- + H+
Initial concentration Ca 0 0
Concentration at equilibrium Ca - x x x


As the acid is weak, the Ka is small, so the equilibrium lies well to the left, so we assume that
Ca – x ≅ Ca, then the equilibrium expression becomes:

Ka = x2/Ca = [H+]2/Ca

Then,

[H+] = SQRT (KaCa) = (Ka)1/2 (Ca)1/2

taking the negative logarithms,

pH = ½ pKa – ½ log Ca

Weak base:
Only some small fraction of molecules in solution dissociates to anion and proton, being x its concentration at equilibrium:

BOH OH- + B+
Initial concentration Cb 0 0
Concentration at equilibrium Cb - x x x


As the base is weak, the Kb is small, so the equilibrium lies well to the left, so we assume that
Cb – x ≅ Cb, then the equilibrium expression becomes:

Kb = X2/Cb = [OH-]2/Cb

Then:

[OH-] = SQRT (KbCb) = (Kb)1/2 (Cb)1/2

taking the negative logarithms,

pOH = ½ pKb – ½ log Cb

pH = 14 - pOH

Buffers
Weak acid plus the salt of the weak acid (i.e a weak acid in the presence of its conjugate base).

In this case the weak acid, HA, with concentration Ca, is in solution with a salt of a common cation.
For example, if the salt NaA has concentration Cb, the [A] in the solution, due to the salt alone, is
also Cb, since NaA is 100% dissociated (all salts ionize completely in aqueous solutions).

HA A- + H+
Initial concentration Ca Cb 0
Concentration at equilibrium Ca - x Cb + x x


Due to the presence of the common ion (from the salt), A, the equilibrium will be shifted even further left than suggested by the acid small Ka value. Consequently, it is safe to assume that,
Ca − x ≈ Ca and Cb + x ≅ Cb. The equilibrium expression becomes,

Ka = x Cb/Ca= [H+] Cb/Ca

[H+] = Ka Ca/Cb

Taking − log of both sides yields,

pH = pKa + log Cb/Ca

This is called the Henderson-Hasselbalch equation and is useful for estimating the pH
of a buffer solution.

Weak base plus the salt of the weak base (i.e a weak base in the presence of its conjugate acid)
In this case the weak base, BOH, with concentration Cb, is in solution with a salt of a common anion, with concentration Ca.

BOH B+ + OH-
Initial concentration Cb Ca 0
Concentration at equilibrium Cb - x Ca + x x


Due to the presence of the common ion (from the salt), B+, the equilibrium will be shifted even further left than suggested by the base small Kb value. Consequently, it is safe to assume that,
Cb − x ≈ Cb and Ca + x ≅ Ca. The equilibrium expression becomes,

Kb = x Ca/Cb = [OH-] Ca/Cb

[OH-] = Kb Cb/Ca

Taking − log of both sides yields,
pOH = pKb – log (Cb/Ca)

since pKb = 14 - pKa and pOH = 14 - pH

then:

pH = pKa + log Cb/Ca

And we have again the Henderson-Hasselbalch equation. In this case, the pKa is for the conjugate acid of the weak base and Cb and Ca are the concentrations of the weak base and its conjugate acid respectively.

Amphiprotic substance (i.e. HA-, present in the solution of acidic salts)
The challenge is, HA- hydrolyses and dissociates at the same time and it is not obvious which of these processes will be be responsible for the final pH, moreover, it is very likely that pH can be attributed to some equilibrium between both reactions.

Ka1 = [H+] [HA-] / [H2A]
Ka2 = [H+] [A2-] / [HA-]
CHA- = [H2A] + [HA-] + [A2-]

CHA- is the concentration of the source of the amphiprotic substance

H+ ions are produced in the dissociation reaction (together with A2-) and consumed in the hydrolysis (yielding H2A), so their concentration is:

[H+] = [A2-] - [H2A]

we can rewrite it in the form:

[H+]=Ka2 [HA-] / [H+] – [H+] [HA-] / Ka1

or, after rearranging

[H+]2 = Ka1 Ka2 [HA-] / ([HA-] + Ka1)

If neither dissociation nor hydrolysis goes too far, and [HA-] = CHA-. If so

[H+] = SQRT (cHA- Ka1 Ka2 / (cHA- + Ka1)


If the CHA- is sufficiently larger than Ka1 we can neglect Ka1 and whole equation takes form

[H+] ≅ SQRT(Ka1 Ka2) = Ka1½ Ka2½

or

pH = ½ (pKa1 + pKa2)

Titration
Titration is a procedure used to determine the concentration of an acid or base. This is accomplished by reacting a known volume of a solution of an unknown concentration with a known volume of a solution of known concentration. When the number of acid molecules equals the number of base molecules added (or vice versa), the equivalence point is reached.
The equivalence point in a titration is estimated in two common ways: either by using a graphical method, plotting the pH of the solution as a function of added titrant by using a pH meter or by watching for a color change of an added indicator. Indicators are weak organic acids or bases that have different colors in their undissociated and dissociated states.
For further information about our titration products please visit our Titration page.

Our portfolio of Acids and Bases consists of:

  • Inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, phosphoric acid or boric acid, etc.,
  • Organic acids are acetic acid, formic acid, citric acid, lactic acid, oxalic acid, ascorbic acid, EDTA, etc.,
  • Fatty acids such as octanoic acid (caprylic acid), oleic acid,
  • Amino acids (see also Amino acids page), which are especially important in the field of biochemistry/Life Sciences such as aspartic acid, glutamic acid or lysine, among others. Amino acids are the building blocks of proteins and play a key role in most biological processes. In fact, they can have both acidic and basic (amphoteric) behavior, depending on the pH of the solution, because they have an amino group (basic) and a carboxylic group (acidic) in the same molecule,
  • Inorganic bases, the most common ones are sodium hydroxide (caustic soda), potassium hydroxide (caustic potash), ammonia in solution, bicarbonates, calcium or magnesium hydroxides, etc,
  • Organic bases, among them are pyridine, tetrabutylammonium hydroxyde, triethanolamine, triethylamine, etc.


It is of vital importance to choose the right product with the appropriate quality grade adapted to your requirements to achieve and obtain high-quality, reliable and accurate results. We offer a broad range of quality grades with strictly guaranteed specifications, enabling the selection of the right product for your specific application:

  • Reagents for analysis (p.a.) according to ISO (International Organization for Standardization), ACS (American Chemical Society) and pharmacopoeia specifications for reagents (Reag. Ph. Eur., Reag. USP).
  • Ultrapure acids for trace metal analysis (ppb, ppt) by AAS, GF-AAS, ICP-OES, ICP-MS.
  • For HPLC or for UV applications.
  • Pharma grade: raw materials for the pharmaceutical industry in manufacturing processes (e.g. for pH adjustments), and as excipients in the final formulation, complying with the pharmacopoeia specifications (monographs), such as US Pharmacopea/National Formulary (USP-NF), European Pharmacopoeia (EP or Ph. Eur.), British Pharmacopoeia (BP), etc., and GMP-IPEC grade, including regulatory documents.
  • Reagents for Life Sciences: BioChemica, for molecular biology or for cell culture.
  • Pure products for general use.
  • Volumetric solutions (standards), concentrated and ready to use, for quantitative analysis.
  • Solutions for volumetric analysis / titration and for the determination of nitrogen (proteins) by means of the Kjeldahl method.
  • For clinical diagnosis, such as picric acid.
  • Products for synthesis.
  • Technical grade or industrial grade.
  • Food grade according to European regulations (EC) or Food Chemicals Codex (FCC).
  • VINIKIT, for wine analysis.


Acids and bases at ITW Reagents
At ITW Reagents we supply high quality acids and bases under the PanReac AppliChem brand for all relevant industries, such as pharmaceutical and food industry, testing in general analysis laboratories, quality control, research, life sciences, environmental analysis, and others. All products are manufactured using the Integrated Quality Management System according to ISO 9001, ISO 14001 and ISO 45001 standards. With our more than 80 years of experience as a manufacturer, you can benefit from our exceptional know-how in acids and bases under strict quality control, commercial and technical support strongly committed to our customers, constant stock level with a stable supply chain and a global distribution network.

Applications of acids and bases
In chemical quality control labs, research and development or in innovation departments of any industry or institution, also when using raw materials in industrial processes for production of pharmaceuticals or in any organic synthesis or purification processes.

Analytical reagents in standard procedures, pH adjustments, qualitative and quantitative analysis, instrumental analysis, wet chemistry analysis and testing, educational chemistry experiments, digestion of samples, catalysts in chemical reactions, sample preparation in trace metal analysis, wastewater testing, etc.

In water treatment, manufacturing of paper, fertilizers, soaps, detergents, cleaning agents, cleaning-in-place (CIP), synthesis of nylon, explosives, production of organic compounds (such as vinyl chloride and dichloroethane for PVC), manufacturing of synthetic resins, dyestuffs, pharmaceuticals, petroleum catalysts, insecticides and antifreeze, as well as in various processes such as oil well acidizing, aluminum reduction, refining metals, picking of steel, electroplating, battery production, etc.

Sectors

  • Analytical Laboratories, Quality Control, Chemical and Biochemical labs
  • Research, Development, and Innovation (R&D)
  • Biopharmaceutical and Pharmaceutical development and manufacturing
  • Life Sciences
  • Cosmetics and Healthcare
  • Food and Beverages
  • Inorganic and Organic synthesis
  • Educational or academic institutions
  • Paper industry
  • Soap and detergent industry
  • Metallurgy
  • Agriculture
  • Pool maintenance


Pack sizes and packaging materials
From mg to tons for solids and from mL to 1000 L for liquids, in a large variety of packaging sizes and materials, we select the most convenient containers assuring the preservation of the product quality, the safety on transport and use, and the protection of the environment.

UN Certified packaging
The regulations for the transport of hazardous materials require the use of approved packaging. It defines the characteristics that containers and packaging must meet according to the product, its hazardousness and the maximum quantity it can contain. This information appears on UN approved containers.
All packaging used by PanReac AppliChem branded products scrupulously comply with the regulations in force (ADR, RID IMDG, ICAO-IATA).

Packaging materials

  • Standard containers: Glass bottles, HDPE bottles, PC bottles, HDPE canisters, HDPE drums, PP pails/buckets.
  • Special bottles/containers: For liquid corrosive products, such as acids and bases, we use special glass bottles with pouring ring. The pouring ring prevents from any drop sliding down the outside of the bottle that could damage the label, the surface area or could harm the user.
  • Square plastic (HDPE) bottles for volumetric solutions, with a great stability, special for automatic titrators.
  • We use specially selected teflon bottles for trace metal analysis ultra-pure acids. The material is controlled prior to the bottle manufacture. Every bottle is leached with hot acid during two weeks in order to eliminate any contamination material due to metallic traces.
  • Sol-Pack (bag in box, cubitainer) consists of a 10 L-collapsible polyethylene bag and an outer cardboard box, forming a light, practical and easily disposable pack. It incorporates a tap, which allows convenient dosing down to the last drop. Main advantages: saving of up to 60% compared with 1 litre bottles. Air does not enter the collapsible bag, ensuring product preservation. Reduced risk of contamination or carbonatation. A more environmentally friendly alternative to plastic bottles, as less packaging waste is generated.
  • Larger quantities: Sodium hydroxide solutions and hydrochloric acid are available in IBC containers (up to 1000 L). Obtain the maximum capacity with a minimum space. IBCs are used to transport and store large amounts of liquids, for chemical, food, cosmetics, and pharmaceutical industries. UN certified.
  • Plastic (PP) pails/buckets for solids from 5 kg to 25 kg, UN certified, suitable for chemical, food, cosmetics and pharmaceutical industries.

We offer our customers several accessories and tools, such as taps, wrenches and adapters, to facilitate the opening and dispensing of containers.

See more info at Packaging

Safety
Both acids and bases are chemicals that present health hazards if improperly handled or stored. It is extremely important to handle and store chemicals safely to avoid spills in the workplace, fires, explosions, release of toxic gas and personal injuries. Safety Data Sheets (SDS) will provide information on how to protect yourself from potential adverse health effects, how to correctly handle the chemical, avoid possible dangers, properly dispose of the chemical, and more. It is critical to the safety of yourself and others to handle chemicals with caution and follow the proper protocols. Reading the entire SDS sheet can help avoid accidents and potential injuries from improper chemical usage. SDS or Safety Data Sheets, formally known as MSDS (Material Safety Data Sheets) are the internationally recognized format for communicating the use, handling, and storage of hazardous products. All Safety Data Sheet (SDS) are available on our webpage, please read carefully the SDS before using the product.

Purity
To minimize the risk of user exposure to acids and bases and save preparation time, we offer a wide range of prepared solutions in different concentrations with the highest quality raw materials and strict quality control to ensure exact concentration and maximum purity.

Examples of acids and bases in different concentrations

Hydrochloric acid, HCl, CAS number 7647-01-0:

PRODUCT CODE PRODUCT NAME
381020 Hydrochloric Acid 37%, HCl 37%, for trace metal analysis (ppm)
471020 Hydrochloric Acid 37%, HCl 37%, (max. 0.0000005% Hg) (Reag. USP) for analysis, ACS, ISO
131020 Hydrochloric Acid 37%, HCl 37%, (Reag. USP) for analysis, ACS, ISO
141020 Hydrochloric Acid 37%, HCl 37%, (USP-NF, BP, Ph. Eur.) pure, pharma grade
201020 Hydrochloric Acid 37%, HCl 37%, (E-507, F.C.C.) food grade
211020 Hydrochloric Acid 37%, HCl 37%, technical grade
711019 Hydrochloric Acid 35%, HCl 35%, for trace metal analysis (ppt)
721019 Hydrochloric Acid 35%, HCl 35%, for trace metal analysis (ppb)
132176 Hydrochloric Acid 32%, HCl 32%, for analysis, ISO
212176 Hydrochloric Acid 32%, HCl 32%, technical grade
133378 Hydrochloric Acid 25%, HCl 25%, for analysis, ISO
A0658 Hydrochloric Acid 25%, HCl 25%, for analysis
143378 Hydrochloric Acid 25%, HCl 25%, pure
203378 Hydrochloric Acid 25%, HCl 25%, (E-507, F.C.C.) food grade
A3397 Hydrochloric acid 20%, HCl 20%, for analysis
142523 Hydrochloric Acid 20%, HCl 20%, pure
146316 Hydrochloric Acid 15%, HCl 15%, pure
123006 Hydrochloric Acid 10%, HCl 10%, w/w for analysis
143006 Hydrochloric Acid 10%, HCl 10%, w/w (USP-NF, Ph. Eur.) pure, pharma grade
213006 Hydrochloric Acid 10%, HCl 10%, w/w technical grade
182884 Hydrochloric Acid 0.01 mol/L, HCl 0.01 mol/L, (0.01 N) volumetric solution
182107 Hydrochloric Acid 0.05 mol/L, HCl 0.05 mol/L, (0.05 N) volumetric solution
181023 Hydrochloric Acid 0.1 mol/L, HCl 0.1 mol/L, (0.1 N) volumetric solution
303110 Hydrochloric Acid 0.1 mol (3.646 g HCl) to prepare 1 L of 0.1 N solution
182318 Hydrochloric Acid 0.25 mol/L, HCl 0.25 mol/L, (0.25 N) volumetric solution
185423 Hydrochloric Acid 0.310 mol/L, HCl 0.310 mol/L, (1.128% w/v) volumetric solution
181022 Hydrochloric Acid 0.5 mol/L, HCl 0.5 mol/L, (0.5 N) volumetric solution
181021 Hydrochloric Acid 1 mol/L, HCl 1 mol/L, (1 N) volumetric solution
186985 Hydrochloric Acid 1 mol/L, HCl 1 mol/L, (1 N) (Reag. Ph. Eur.) volumetric solution
303112 Hydrochloric Acid 1 mol (36.461g HCl) to prepare 1 L of 1N solution
182108 Hydrochloric Acid 2 mol/L, HCl 2 mol/L, (2 N) volumetric solution
182057 Hydrochloric Acid 3 mol/L, HCl 3 mol/L, (3 N) volumetric solution
182552 Hydrochloric Acid 4 mol/L, HCl 4 mol/L, (4 N) volumetric solution
192109 Hydrochloric Acid 5 mol/L, HCl 5 mol/L, (5 N) pharma grade
182109 Hydrochloric Acid 5 mol/L, HCl 5 mol/L, (5 N) volumetric solution
182883 Hydrochloric Acid 6 mol/L, HCl 6 mol/L, (6 N) volumetric solution
187051 Hydrochloric Acid 10 mol/L, HCl 10 mol/L, (10 N) volumetric solution



Sodium hydroxide, NaOH, CAS number 1310-73-2:

PRODUCT CODE PRODUCT NAME
131687 Sodium Hydroxide 98.0%, NaOH 98.0%, pellets (Reag. USP) for analysis, ACS, ISO
631687 Sodium Hydroxide 97.0-100.5%, NaOH 97.0-100.5%, pellets, GMP - IPEC grade
141687 Sodium Hydroxide 98.0-100.5%, NaOH 98.0-100.5%, pellets (USP-NF, BP, Ph. Eur.) pure, pharma grade
A0991 Sodium Hydroxide 97.0-100.5%, NaOH 97.0-100.5%, pellets (USP-NF, Ph. Eur.) pure, pharma grade
141929 Sodium Hydroxide 98.0-100.5%, NaOH 98.0-100.5%, pearls (USP-NF, BP, Ph. Eur.) pure, pharma grade
145881 Sodium Hydroxide 98%, NaOH 98%, micropearls pure
201687 Sodium Hydroxide 98.0-100.5%, NaOH 98.0-100.5%, pellets (E-524, F.C.C.) food grade
211687 Sodium Hydroxide 98%, NaOH 98%, pellets technical grade
211929 Sodium Hydroxide 98%, NaOH 98%, pearls technical grade
142404 Sodium Hydroxide solution 50%, NaOH 50%, w/w pure
141571 Sodium Hydroxide solution 50%, NaOH 50%, w/v pure
141220 Sodium Hydroxide solution 40%, NaOH 40%, w/w pure
171220 Sodium Hydroxide solution 40%, NaOH 40%, w/w for the determination of nitrogen
121593 Sodium Hydroxide solution 40%, NaOH 40%, w/v for analysis
126682 Sodium Hydroxide solution 32%, NaOH 32%, w/w for analysis
146682 Sodium Hydroxide solution 32%, NaOH 32%, w/w pure
176682 Sodium Hydroxide solution 32%, NaOH 32%, w/w for nitrogen determination
216682 Sodium Hydroxide solution 32%, NaOH 32%, w/w technical grade
122666 Sodium Hydroxide solution 32%, NaOH 32%, w/v for the determination of nitrogen
Z44320 Sodium Hydroxide solution 30%, NaOH 30%, w/w pure, pharma grade
144320 Sodium Hydroxide solution 30%, NaOH 30%, w/w pure, pharma grade
171690 Sodium Hydroxide solution 30%, NaOH 30%, w/v
143402 Sodium Hydroxide solution 25%, NaOH 25%, w/w pure
181845 Sodium Hydroxide 0.01 mol/L, NaOH 0.01 mol/L, (0.01N) volumetric solution
621845 Sodium Hydroxide 0.01 mol/L, NaOH 0.01 mol/L, (0.01N) VINIKIT, for wine analysis
183397 Sodium Hydroxide 0.02 mol/L, NaOH 0.02 mol/L, (0.02N) standard volumetric solution
624785 Sodium Hydroxide N/49, NaOH N/49, VINIKIT for wine analysis
182153 Sodium Hydroxide 0.05 mol/L, NaOH 0.05 mol/L, (0.05N) volumetric solution
181694 Sodium Hydroxide 0.1 mol/L, NaOH 0.1 mol/L, (0.1N) (Reag. USP, Ph. Eur.) volumetric solution
181693 Sodium Hydroxide 0.1 mol/L, NaOH 0.1 mol/L, (0.1N) volumetric solution
303125 Sodium Hydroxide 0.1 mol (4.000 g NaOH) to prepare 1 L of 0.1N solution
182284 Sodium Hydroxide 0.1 mol/L, NaOH 0.1 mol/L, (0.1N) in ethanol volumetric solution
183154 Sodium Hydroxide 0.111 mol/L, NaOH 0.111 mol/L, (0.111N) according to Dornic volumetric solution
182971 Sodium Hydroxide 0.2 mol/L, NaOH 0.2 mol/L, (0.2N) volumetric solution
624782 Sodium Hydroxide N/4.9, NaOH N/4.9, VINIKIT for wine analysis
182155 Sodium Hydroxide 0.25 mol/L, NaOH 0.25 mol/L, (0.25N) volumetric solution
183337 Sodium Hydroxide 0.313 mol/L, NaOH 0.313 mol/L, (0.313N) standard volumetric solution
182156 Sodium Hydroxide 0.3546 mol/L, NaOH 0.3546 mol/L, (N/2.82) volumetric solution
181692 Sodium Hydroxide 0.5 mol/L, NaOH 0.5 mol/L, (0.5N) volumetric solution
192415 Sodium Hydroxide 1 mol/L, NaOH 1 mol/L, (1N) pharma grade
182415 Sodium Hydroxide 1 mol/L, NaOH 1 mol/L, (1N) (Reag. USP, Ph. Eur.) volumetric solution
186982 Sodium Hydroxide 1 mol/L, NaOH 1 mol/L, (1N) (Reag. Ph. Eur.) volumetric solution
181691 Sodium Hydroxide 1 mol/L, NaOH 1 mol/L, (1N) volumetric solution
303126 Sodium Hydroxide 1 mol (40.00 g NaOH) to prepare 1 L of 1N solution
A6579 Sodium Hydroxide solution (1 M), NaOH 1 mol/L, (1 M) for molecular biology
185528 Sodium Hydroxide 1.02 mol/L, NaOH 1.02 mol/L, (1.02N) volumetric solution
185776 Sodium Hydroxide 1.2 mol/L, NaOH 1.2 mol/L, (1.2N) volumetric solution
182158 Sodium Hydroxide 2 mol/L, NaOH 2 mol/L, (2N) volumetric solution
183466 Sodium Hydroxide 4 mol/L, NaOH 4 mol/L, (4N) volumetric solution
192159 Sodium Hydroxide 5 mol/L, NaOH 5 mol/L, (5N) pharma grade
182159 Sodium Hydroxide 5 mol/L, NaOH 5 mol/L, (5N) volumetric solution
AL6406 Sodium Hydroxide 6 mol/L, NaOH 6 mol/L, (6N) pharma grade
193508 Sodium Hydroxide 10 mol/L, NaOH 10 mol/L, (10N) pharma grade
183508 Sodium Hydroxide 10 mol/L, NaOH 10 mol/L, (10N) volumetric solution



Sulfuric acid, H2SO4, CAS number 7664-93-9:

PRODUCT CODE PRODUCT NAME
173163 Sulfuric Acid 98%, H2SO4 98%, for the determination of nitrogen
471058 Sulfuric Acid 95-98%, H2SO4 95-98%, (max. 0.0000005% Hg) (Reag. USP) for analysis, ACS, ISO
141058 Sulfuric Acid 95-98%, H2SO4 95-98%, (USP-NF, BP, Ph. Eur.) pure, pharma grade
721058 Sulfuric Acid 93-98%, H2SO4 93-98%, for trace metal analysis (ppb)
131058 Sulfuric Acid 96%, H2SO4 96%, (Reag. Ph. Eur.) for analysis, ISO
A0655 Sulfuric acid 95-97%, H2SO4 95-97%, for analysis
211058 Sulfuric Acid 96%, H2SO4 96%, technical grade
121010 Sulfuric Acid 90-91%, H2SO4 90-91%, according to Gerber for analysis
123374 Sulfuric acid 75%, H2SO4 75%, for analysis
123863 Sulfuric Acid 72%, H2SO4 72%, for analysis
142934 Sulfuric Acid 50%, H2SO4 50%, (w/w) pure
127102 Sulfuric Acid 40%, H2SO4 40%, for analysis
122448 Sulfuric Acid 25%, H2SO4 25%, for analysis
143323 Sulfuric Acid 20%, H2SO4 20%, pure
145882 Sulfuric Acid 10%, H2SO4 10%, w/v pure, pharma grade
621062 Sulfuric Acid solution 1/3, H2SO4 solution 1/3, w/v VINIKIT, for wine analysis
182102 Sulfuric Acid 0.01 mol/L, H2SO4 0.01 mol/L, (0.02N) volumetric solution
182103 Sulfuric Acid 0.025 mol/L, H2SO4 0.025 mol/L, (0.05N) volumetric solution
181061 Sulfuric Acid 0.05 mol/L, H2SO4 0.05 mol/L, (0.1N) volumetric solution
303114 Sulfuric Acid 0.05 mol, H2SO4 (4.904 g H2SO4) to prepare 1 L of 0.1N solution
182011 Sulfuric Acid 0.1 mol/L, H2SO4 0.1 mol/L, (0.2N) volumetric solution
183335 Sulfuric Acid 0.1275 mol/L, H2SO4 0.1275 mol/L, (0.255N) volumetric solution
181060 Sulfuric Acid 0.25 mol/L, H2SO4 0.25 mol/L, (0.5N) volumetric solution
181059 Sulfuric Acid 0.5 mol/L, H2SO4 0.5 mol/L, (1N) volumetric solution
185775 Sulfuric Acid 0.9 mol/L, H2SO4 0.9 mol/L, (1.8N) volumetric solution
182105 Sulfuric Acid 1 mol/L, H2SO4 1 mol/L, (2N) volumetric solution
183426 Sulfuric Acid 2 mol/L, H2SO4 2 mol/L, (4N) volumetric solution
182106 Sulfuric Acid 2.5 mol/L, H2SO4 2.5 mol/L, (5N) volumetric solution



Nitric acid, HNO3, CAS number 7697-37-2:

PRODUCT CODE PRODUCT NAME
121038 Nitric Acid fuming 99.5%, HNO3 99.5%, (Reag. Ph. Eur.) for analysis
711037 Nitric Acid 69%, HNO3 69%, for trace metal analysis (ppt)
721037 Nitric Acid 69%, HNO3 69%, for trace metal analysis (ppb)
381037 Nitric Acid 69%, HNO3 69%, for trace metal analysis (ppm)
471037 Nitric Acid 69%, HNO3 69%, (max. 0.0000005% Hg) for analysis
131037 Nitric Acid 69%, HNO3 69%, (Reag. USP, Ph. Eur.) for analysis, ACS, ISO
141037 Nitric Acid 69%, HNO3 69%, (USP-NF, BP, Ph. Eur.) pure, pharma grade
211037 Nitric Acid 69%, HNO3 69%, technical grade
121737 Nitric Acid 53%, HNO3 53%, for analysis
127084 Nitric Acid 20%, HNO3 20%, for analysis
181040 Nitric Acid 0.1 mol/L, HNO3 0.1 mol/L, (0.1N) volumetric solution
181039 Nitric Acid 1 mol/L, HNO3 1 mol/L, (1N) volumetric solution
182112 Nitric Acid 2 mol/L, HNO3 2 mol/L, (2N) volumetric solution



Acetic acid, CH3COOH, CAS number 64-19-7:

PRODUCT CODE PRODUCT NAME
361008 Acetic Acid glacial 99.8%, CH3COOH 99.8%, for HPLC
131008 Acetic Acid glacial 99.7%, CH3COOH 99.7%, (Reag. USP, Ph. Eur.) for analysis, ACS, ISO
141008 Acetic Acid glacial 99.5-100.5%, CH3COOH 99.5-100.5%, (USP, BP, Ph. Eur.) pure, pharma grade
A3701 Acetic Acid 100%, CH3COOH 100%, BioChemica
122703 Acetic Acid 96%, CH3COOH 96%, for analysis
121556 Acetic Acid 80%, CH3COOH 80%, for analysis
196358 Acetic Acid 36%, CH3COOH 36%, (USP-NF) pharma grade
196884 Acetic Acid 25%, CH3COOH 25%, w/w pharma grade
181009 Acetic Acid 1 mol/L, CH3COOH 1 mol/L, (1N) volumetric solution



Ammonia, NH3/NH4OH, CAS number 1336-21-6:

PRODUCT CODE PRODUCT NAME
131130 Ammonia 30% (as NH3) for analysis, ACS
141130 Ammonia 30% (as NH3) (USP-NF, BP, Ph. Eur.) pure, pharma grade
121129 Ammonia 25% (as NH3) (Reag. USP, Ph. Eur.) for analysis
141129 Ammonia 25% (as NH3) (BP, Ph. Eur.) pure, pharma grade
121128 Ammonia 20% (as NH3) for analysis
A2616 Ammonia 10% (as NH3) for analysis



Potassium hydroxide, KOH, CAS number 1310-58-3:

PRODUCT CODE PRODUCT NAME
131515 Potassium Hydroxide 85%, KOH 85%, pellets (Reag. USP) for analysis, ACS
121515 Potassium Hydroxide 85%, KOH 85%, pellets for analysis
141515 Potassium Hydroxide 85%, KOH 85%, pellets (USP-NF, BP, Ph. Eur.) pure, pharma grade
201515 Potassium Hydroxide 85%, KOH 85%, pellets (E-525, F.C.C.) food grade
211514 Potassium Hydroxide 90%, KOH 90%, flakes technical grade
142403 Potassium Hydroxide solution 50%, KOH 50%, pure
181521 Potassium Hydroxide 0.1 mol/L, KOH 0.1 mol/L, (0.1N) volumetric solution
182146 Potassium Hydroxide 0.1 mol/L, KOH 0.1 mol/L, (0.1N) in ethanol (Reag. USP, Ph. Eur.) volumetric solution
183354 Potassium Hydroxide 0.23 mol/L, KOH 0.23 mol/L, (0.23N) volumetric solution
181518 Potassium Hydroxide 0.5 mol/L, KOH 0.5 mol/L, (0.5N) volumetric solution
181519 Potassium Hydroxide 0.5 mol/L, KOH 0.5 mol/L, (0.5N) in ethanol (Reag. USP) volumetric solution
181520 Potassium Hydroxide 0.5 mol/L, KOH 0.5 mol/L, (0.5N) in methanol volumetric solution
181517 Potassium Hydroxide 1 mol/L, KOH 1 mol/L, (1N) volumetric solution
621517 Potassium Hydroxide 1 mol/L, KOH 1 mol/L, (1N) VINIKIT, for wine analysis



Phosphoric acid, H3PO4, CAS number 1310-58-3:

PRODUCT CODE PRODUCT NAME
131032 ortho-Phosphoric Acid 85%, H3PO4 85%,for analysis, ACS, ISO
A0989 ortho-Phosphoric Acid 85%, H3PO4 85%, for analysis
141032 ortho-Phosphoric Acid 85%, H3PO4 85%, (USP-NF, BP, Ph. Eur.) pure, pharma grade
147067 ortho-Phosphoric Acid 25%, H3PO4 25%, pure
127143 ortho-Phosphoric Acid 10%, H3PO4 10%, for analysis
147143 ortho-Phosphoric Acid 10%, H3PO4 10%, (Ph. Eur., USP-NF) pure, pharma grade
147146 ortho-Phosphoric Acid 5%, H3PO4 5%, pure
A8582 ortho-Phosphoric Acid (1.33 M), H3PO4 (1.33 M)



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