The mass $\%$ of urea solution is $6$. The total weight of the solution is $1000 \ g$. What is its concentration in $mol \ L^{-1}$? (Density of water $= 1.0 \ g \ mL^{-1}$)
$(C = 12 \ u, N = 14 \ u, O = 16 \ u, H = 1 \ u)$

At $T \ (K)$, $100 \ g$ of $98\%$ $H_2SO_4$ $(w/w)$ aqueous solution is mixed with $100 \ g$ of $49\%$ $H_2SO_4$ $(w/w)$ aqueous solution. What is the mole fraction of $H_2SO_4$ in the resultant solution?
(Given: Atomic mass $H = 1 \ u; S = 32 \ u; O = 16 \ u$)
(Assume that temperature after mixing remains constant)

Calculate the mole fraction of urea in an aqueous solution of $1 \ m$ urea $(NH_2CONH_2)$.

The value of which of the following units of concentration will not change with the change in temperature?

The volume of ethyl alcohol (density $1.15 \text{ g/cc}$) that has to be added to prepare $100 \text{ cc}$ of $0.5 \text{ M}$ ethyl alcohol solution in water is: (in $\text{ cc}$)

Which of the following relationships between $Normality$ and $Molarity$ is correct?