The density of an aqueous solution of sulfuric acid is 1.36 g/mL and the concentration is 3.43 M. What is the concentration of this solution in percent by mass?

2.40%

Explanation:

Density of a substance is given as the mass divided by the volume,

Hence from the question,

density of sulfuric acid = 1.35 g/mL

i. e.

1mL of sulfuric acid solution = 1.35 g of sulfuric acid,

Hence,

1000mL of sulfuric acid solution = 1.35 * 1000 g of sulfuric acid,

i. e.

1000mL of sulfuric acid solution = 13500 g of sulfuric acid,

Now, Molarity of a solution is given by the moles of solute per liter of the solution.

Hence,

M = moles of solute / volume of solution (in L)

From question, '

3.43 M of sulfuric acid,

Hence,

In 1 L of solution, 3.34 moles of sulfuric acid are present,

Now,

Moles are calculated as the given mass divided by the molecular mass.

The molecular mass of sulfuric acid is 98 g / mol

moles = (mass / molecular mass)

therefore,

mass = moles * molecular mass

i. e.

mass of sulfuric acid = 3.34 mol * 98 g/mol = 327.32 g

Now, to calculate the mass percentage of sulfuric acid, is given by the mass of sulfuric acid divided by the mass of the total solution multiplied by 100.

therefore,

mass of sulfuric acid = 327.32 / 13600 * 100

Hence, mass of sulfuric acid = 2.40%