Question

1.2 g of a substance $A$ is dissolved in $250c{m}^3$ of the solution to give a 0.1 molar solution. What is the molar mass of the compound $A$?

• A. 12 $gmo{l}^{-1}$
• B. 24 $gmo{l}^{-1}$
• C. 48 $gmo{l}^{-1}$
• D. None of these

Answer 1

Answer: (C)

48 $gmo{l}^{-1}$

Given,

substance weight = 1.2g

solution= 250 cubic cm = 0.25 l

molarity = 0.1

we have to find the molar mass of a substance

molarity = mole /volume

$mole=molarity\ast volume$

$givenmass/molarmass$ = $molarity\ast volume$

$1.2/molarmass=0.1\ast 0.25$

molar mass = 48g/mole

molar mass of compound A is 48