Question

Calculate the normality of each of the following solutions. a. \(0.250 M \mathrm{HCl}\) b. \(0.105 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}\) c. \(5.3 \times 10^{-2} M \mathrm{H}_{3} \mathrm{PO}_{4}\)

Short answer

The normality of the solutions are: a. 0.250 N for 0.250 M HCl. b. 0.210 N for 0.105 M H2SO4. c. \(15.9 \times 10^{-2}\) N for \(5.3 \times 10^{-2}\) M H3PO4.

Step-by-step solution

Identify the number of acidic hydrogens present in the given acids.

Before calculating the normality of the solutions, we need to recognize the number of acidic hydrogens in the given acids: a. HCl has 1 acidic hydrogen. b. H2SO4 has 2 acidic hydrogens. c. H3PO4 has 3 acidic hydrogens.

Calculate the normality of the given solutions.

Now using the formula N = M × n, let's calculate the normality of the following solutions: a. For 0.250 M HCl, N = M × n = 0.250 M × 1 N = 0.250 N b. For 0.105 M H2SO4, N = M × n = 0.105 M × 2 N = 0.210 N c. For \(5.3 \times 10^{-2}\) M H3PO4, N = M × n = \(5.3 \times 10^{-2}\) M × 3 N = \(15.9 \times 10^{-2}\) N Now, we have calculated the normality of the given solutions. The normality of 0.250 M HCl is 0.250 N. The normality of 0.105 M H2SO4 is 0.210 N. The normality of \(5.3 \times 10^{-2}\) M H3PO4 is \(15.9 \times 10^{-2}\) N.

Key concepts

Acidic Hydrogens

Acidic hydrogens are the hydrogen atoms in a compound that can be released as protons ( H⁺ ) when dissolved in water. It's important to identify the number of acidic hydrogens to calculate the normality of a solution since normality relates to the equivalent concentration of the solution.

For different acids, the number of acidic hydrogens can vary:

• In HCl , there is 1 acidic hydrogen.
• In H₂SO₄ , there are 2 acidic hydrogens.
• In H₃PO₄ , there are 3 acidic hydrogens.

Knowing the number of acidic hydrogens helps us determine how many moles of protons are released per mole of acid, which is crucial for calculating normality.

Molarity

Molarity is a measure of the concentration of a solute in a solution, specifically the number of moles of solute per liter of solution. It is denoted by the letter M and is usually expressed in units of mol/L .

When discussing acids or bases, understanding molarity is essential as it forms the basis for calculating other concepts like normality. For instance:

• 0.250 M HCl means there are 0.250 moles of HCl in each liter of solution.
• 0.105 M H₂SO₄ indicates that each liter contains 0.105 moles of H₂SO₄ .
• 5.3 × 10^{-2} M H₃PO₄ signifies that there are 5.3 × 10^{-2} moles of H₃PO₄ per liter.

Molarity is crucial in stoichiometric calculations and when preparing solutions for reactions.

Chemical Solutions

Chemical solutions are homogeneous mixtures composed of two or more substances. In a solution, the solute is the substance dissolved, while the solvent is the substance that does the dissolving, typically in greater quantity.

Chemical solutions are fundamental in various scientific experiments and real-world applications, with water being a universal solvent. For instance:

• HCl dissolved in water to create hydrochloric acid solution.
• H₂SO₄ in water forms sulfuric acid solution.
• H₃PO₄ in water results in phosphoric acid solution.

Understanding the properties of chemical solutions is essential for tasks such as titration, where precise concentrations are needed for accurate results.

Acid-Base Chemistry

Acid-base chemistry revolves around the behavior of acids and bases, particularly their ability to donate or accept protons ( H⁺ ). In this field, the concepts of molarity and normality are highly relevant.

An acid is a substance that donates protons, while a base accepts them, leading to reactions that can neutralize each other. The normality of an acid or a base gives a measure of its reactive capacity.

• In acid-base reactions, normality reveals how many equivalents of reactants actually participate.
• For instance, HCl contributes one equivalent per mole, while H₂SO₄ and H₃PO₄ contribute two and three equivalents, respectively.

Understanding these principles helps in balancing chemical equations and predicting the outcome of reactions, particularly in titration processes.