The concentrated sulphuric acid that is peddled commercially is 95% `H_(2)SO_(4)` by weight. If the density of this commerical acid is `1.834 g cm^(-3)`, the molarity of this solution is

Options

A. 17.8 M
B. 12.0 M
C. 10.5 M
D. 15.7 M

Answer

A

Explanation

95% `H_(2)SO_(4)` by weight means 100 g `H_(2)SO_(4)` solution contains 95 g `H_(2)SO_(4)` by mass.
Molar mass of `H_(2)SO_(4)=97 g mol^(-1)`
`"Moles in 95 g"=(95)/(98)=0.969` mole
Volume of 100 g `H_(2)SO_(4)`
`=("mass")/("density")=(100g)/(1.834g cm^(-3))`
`=54.52 cm^(3)=54.52 xx 10^(-3)` L
`"Molarity"=("Moles of solute")/("Volume of solute in L")`
`=(0.969)/(54.52 xx 10^(-3))=17.8 M`