Question

Battery acid is 4.22 M aqueous ${\text{H}}_{\text{2}}\text{S}{\text{O}}_{\text{4}}$ solution, and has density of 1.21 g cm${}^{-3}$. What is the molality of ${\text{H}}_{\text{2}}\text{S}{\text{O}}_{\text{4}}$?

[H = 1, S = 32, O = 16]

Answer 1

Given, Molarity $=4.22$ $M$

$\rho =1.21$ $gm/c{m}^2$

Molecular weight of $H_{2}S{O}_4=98$

$Molality=\frac{1000\times Molarity}{1000\rho -Molarity\times MW}$

$=\frac{1000\times 4.22}{1000\times 1.21-4.22\times 98}$

$=\frac{4220}{1210-413.56}=\frac{4220}{796.44}$

$=5.29$ $mol/kg$