# Calculate the molarity and molality of a solution made by mixing equal volumes of 30% by weight of H2SO4 (density = 1 218 g/ml) and 70% by weight of H2SO4 (density = 1 610 g/ml)

Assume y ml of each solution, a and b, are mixed

Calculate mass of solution using formula,  mass = density(d)  $×$ Volume (V)

Mass of solution a, ma =  1.218  $×$ y  = 1.218y
Mass  H2SO4, msolute a = 30% or $\frac{30×1.218\text{y}}{100}$
msolute a =  0.3654y g
Moles H2SO4, nsolute a  =    (Using formula, moles =  mass, m /Molar mass)
Mass of water, msolvent a = mA- msolute a
msolvent a  = 1.281y – 0.3654y
msolvent a= = 0.8526y  g  or  0.8526 X 10-3y  kg

Similarly for solution B
mb = 1.610y  g
msolute b =

nsolute b  =   $\frac{1.127\text{y}}{98}$ or 11.5y mol
msolvent b  = 1.610y – 1.127y = 0.483y g  or  0.483 $×$ 10-3y kg

When y ml of each solution is mixed
Total volume, V = y + y = 2y ml or  2y $×$ 10-3 L
Total moles of H2SO4, nsolute  = nsolute a   + nsolute b
nsolute=   0.003729y + 11.5y = 0.015229y mol
Total mass of solvent  in kg, msolvent =  msolvent a + msolvent b
msolvent =  1.3356y$×$10-3 kg
Molarity, M =nsolute/V

M  = $\frac{0.015229\text{y}}{2\text{y}×{10}^{-3}}$

M = 7.614M

Molality, m =

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