List of top Chemistry Questions on Molality and Molarity

100 g of a mixture of $NaOH$ and $Na_{2}SO_{4}$ is neutralized by 100 ml of 0.5M $H_{2}SO_{4}$. What is the amount of $Na_{2}SO_{4}$ present in the mixture?}
What is the mole fraction of water in \(10%\) by weight (w/w) of aqueous urea solution? [Given: Molar mass of H, O, C and N are 1, 16, 12 and \(14 \text{ g mol}^{-1}\) respectively.]
Density of 3 M NaCl solution is 1.25 g/mL. The molality of the solution is:
The molarity of a 70%(mass/mass) aqueous solution of a monobasic acid (X) is:

Quantitative analysis of an organic compound (X) shows the following percentage composition. 
C: 14.5% 
Cl: 64.46% 
H: 1.8% 
Empirical formula mass of the compound (X) is: