Commercially available `H_2SO_4` is 98 gms by weight of `H_2SO_4` and 2gms by weight of water. It's density is `1.83 g cm^-3.` Calculate the molality (m) of `H_2SO_4` (molar mass of `H_2SO_4` is `98 mol^-1`)

Options

A. 500 m
B. 20 molal
C. 50 m
D. 200m

Answer

A

Explanation

Answer(1) Weight of `H_2SO_4, W_("solute") = 98 g mol^-1`
Gram molecular weight of `H_2SO_4 = 98` .
Weight of solvent, `w_solvent = 2gms` .
Molality = `W_solute/GMW xx 1000/W_("solvent")` .
`98/98 xx 100/2 `.
`therefore m = 500m` .