A bottle of commercial sulphuric acid `(d = 1.787 g mL^(-1))` is 86% by weight.
a. Whatis molarity of the acid?
b. What volume of the acid has to be used to make `1 L` of `0.2 M H_(2) SO_(4)`?
c. What is the molality of the acid?

Explanation

a. `M = (% "by weight" xx 10 xx d)/(Mw_(2)) = (86 xx 10 xx 1.787)/(98) = 15.68`
b. `M_(1) V_(1) = M_(2) V_(2)`
`15.68 xx V_(1) = 0.2 xx 1`
`V_(1) = 0.01274 L = 12.74 mL`
c. `W_(1) =` Weight of `H_(2) O`
= Weight of solution - Weight of solute
`= 100 - 86 = 14 g`
`m = (W_(2) xx 1000)/(Mw_(2) xx W_(1))`
`= (86 xx 1000)/(98 xx 14) = 62.68`