Calculate the volume of hydrogen obtained by the reaction of zinc with a 200 g sulfuric acid

Calculate the volume of hydrogen obtained by the reaction of zinc with a 200 g sulfuric acid solution with a 15% acid fraction

Given:

m solution (H2SO4) = 200 g;

W (H2SO4) = 15%.

To find:

V (H2) =?

Find a mass of pure sulfuric acid
The mass of the solution is the mass of mixed sulfuric acid with water. To solve the problem, you need a mass of pure sulfuric acid. Determined by the formula:

W = (m substance: m solution) x 100%,

hence m substance = (W x m solution): 100%.

m substance = (15% x 200 g): 100% = 30 g (pure sulfuric acid).

Write the equation of a chemical reaction
When zinc reacts with sulfuric acid, zinc sulfate and hydrogen are formed. Zinc displaces hydrogen from acid.

Zn + H2SO4 = ZnSO4 + H2.

Find the volume of hydrogen
The volume of hydrogen is found by the formula:

m (H2SO4): M (H2SO4) = V (H2): Vm (H2),

hence V (H2) = (m (H2SO4) x Vm (H2)): M (H2SO4).

We find the molecular weight of sulfuric acid using the periodic table.

M (H2SO4) = (1 x 2) + 32 + (16 x 4) = 2 + 32 + 64 = 98 g / mol.

The molar volume is a constant value and is equal to 22.4 l / mol.

Substitute the values: (30 g x 22.4 L / mol): 98 g / mol = 6.85 L.

Answer: V (H2) = 6.85 liters.