Question

If a hazardous bottle is labeled 20.2 % by mass Hydrochloric Acid, HCl, with a density of 1.096 g/mL. Calculate the molarity of the HCl solution.
a. 6.07 M
b. 0.22 M
c. 14.7 M

Answer 1

Answer: The molarity of HCl solution is 6.07 M

Explanation:

We are given:

20.2 % hydrochloric acid solution

This means that 20.2 grams of hydrochloric acid is present in 100 grams of solution

To calculate the volume for given density of substance, we use the equation:

$\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}$

Mass of solution = 100 g

Density of solution = 1.096 mL

Putting values in above equation, we get:

$1.096g/mL=\frac{100g}{\text{Volume of solution}}\\\\\text{Volume of solution}=\frac{100g}{1.096g/mL}=91.24mL$

To calculate the molarity of solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}$

Given mass of hydrochloric acid = 20.2 g

Molar mass of hydrochlroic acid = 36.5 g/mol

Volume of solution = 91.24 mL

Putting values in above equation, we get:

$\text{Molarity of solution}=\frac{20.2\times 1000}{36.5g/mol\times 91.24}\\\\\text{Molarity of solution}=6.07M$

Hence, the molarity of HCl solution is 6.07 M