38. If 125 mL of concentrated sulfuric acid solution (density

1.84 g/mL. 98.3% H₂SO₄ by mass) is diluted to a final volume of 3.01 L, calculate the following information.

a. the mass of pure H₂SO₄ in the 1 25-mL sample.

b. the molarity of the concentrated acid solution

c. the molarity of the dilute acid solution

d. the normality of the dilute acid solution

e. the quantity of the dilute acid solution needed neutralize

45.3 mL of 0.532 M NaOH solution

(a)

Interpretation:

The mass of pure H2SO4 present in pure 125 mL sample is to be calculated.

Concept Introduction:

The mass percentage of a compound present in a solution is calculated by dividing the mass of the compound present in the solution by the total mass of the solution and then multiplying it by 100. The formula for mass percentage is represented as,

mass %=MMt×100 %

Where,

• M represents the mass of the compound present in the solution.
• Mt represents the total mass of solution.

The volume of the concentrated sulfuric acid solution is 125 mL.

The density of the concentrated sulfuric acid solution is 1.84 g/mL.

The mass percentage of H2SO4 in the given solution is 98.3 %.

The relation between mass, volume and density of a substance is given as,

m=VD

Where,

• V represents the volume occupied by the substance.
• m represents the mass of the substance.
• D represents the density of the substance.

Substitute the value of density and volume of sulfuric acid solution in the above equation.

m=125 mL1.84 g/mL=230.00 g

The formula for mass percentage is represented as,

mass %=MMt×100 %

Where,

• M represents the mass of the compound present in the solution

(b)

Interpretation:

The molarity of given concentrated acid solution is to be calculated.

Concept Introduction:

The molarity of a solution is defined as the number of mole of solute dissolved in one liter of the solution. The formula for molarity is given as,

M=nV

Where,

• n represents the number of moles of the solute.
• V represents the volume of the solution.

(c)

Interpretation:

The molarity of the given acid solution after dilution is to be calculated.

Concept Introduction:

The molarity of a solution is defined as the number of moles of solute dissolved in one liter of the solution. The formula for molarity is given as,

M=nV

Where,

• n represents the number of moles of the solute.
• V represents the volume of the solution.

(d)

Interpretation:

The normality of the dilute acid solution is to be calculated.

Concept Introduction:

The normality of a solution is defined as the gram equivalent weight of a solute dissolved in one liter of the solution. The normality of solution is given as:

N=neqV

Where,

• neq represents the number of equivalents of the solute.
• V represents the volume of the solution.

(e)

Interpretation:

The volume of dilute acid solution required to neutralize 45.3 mL of 0.532 M NaOH solution is to be calculated.

Concept Introduction:

Neutralization is the process in which an acid and base react with each other to give salt and water. The general reaction of acid and base is represented as,

AH+BOH→AB+H2O

The molarity of a solution is defined as the number of moles of solute dissolved in one liter of the solution. The formula for molarity is given as,

M=nV

Where,

• n represents the number of moles of the solute.
• V represents the volume of the solution.