Question

Sulphuric acid is 95.8% by mass. Calculate mole fraction and molarity of H₂SO₄ of density 1.91 cm⁻³. (H=1, S=32, O=16 ) (XH₂SO₄ = 0.80730, 17.98M)

Answer 1

Dear Student,

◆ Answer -

Mole fraction = 0.8073

Molarity = 18.67 M

● Explaination -

Consider 100 g of sulphuric acid solution.

Moles of sulphuric acid -

n(H2SO4) = 95.8 / 98

n(H2SO4) = 0.9776 mol

Moles of water are -

n(H2O) = (100-95.8) / 18

n(H2O) = 0.2333 mol

Mole fraction of H2SO4 in the solution will be -

X(H2SO4) = n(H2SO4) / [n(H2SO4) + n(H2O)]

X(H2SO4) = 0.9776 / (0.9776 + 0.2333)

X(H2SO4) = 0.8073

Volume of H2SO4 solution is -

Volume = mass / density

Volume = 100 / 1.91

Volume = 52.36 cm³

Volume = 52.36×10⁻³ L

Molarity of H2SO4 solution is calculated by -

Molarity = n(H2SO4) / Volume of solution

Molarity = 0.9776 / 52.36×10⁻³

Molarity = 18.67 M

Hope this helps you...

Answer 2

Answer:

Molarity = 0.9776 / 52.36×10⁻³

Molarity = 18.67 M