Question

Calculate the molarity, mole fraction, and normality of sulfuric acid. If the mass is 95% and specific gravity is 1.85.

Answer 1

SG = p/p_H2O

where SG = specific graity;
p = density of liquid;
p_H2O = density of water at 4°C = 1000 Kg/m³

Therefore the density of sulfuric acid is
p_H2SO4 = SG x p_H2O
p_H2SO4 = 1.84 x 1000 g/m³
p_H2SO4 = 1840 g/m³ = 1.84 kg/cm³

We know that Density = mass / volume

Assume that we have 2L of sulfuric acid,

mass = 1.84 x 2000ml = 3680

We know that number of moles = weight / molar mass

molar mass of sulfuric acid = 98.080

moles = 3680 / 98.080 = 37.520 moles

Molarity = moles per volume

we have 2L solution

So Molarity = 37.520 moles/2L

= 18.76 mol/L

Moles of sulfuric acid = 37.520 moles
moles of water = 1000/18 = 55.56
Mole fraction = 37.520/ (37.520+55.56) = 0.4030

Normality = weight equivalents / liters

= 9.38 N