The normality of $10 \%$ (weight/volume) acetic acid is ......... $N$.

$10 \, mL$ of $2 \, M \, NaOH$ solution is added to $200 \, mL$ of $0.5 \, M \, NaOH$ solution. What is the final concentration? $............ \, M$

$x$ grams of water is mixed in $69 \ g$ of ethanol. The mole fraction of ethanol in the resultant solution is $0.6$. What is the value of $x$ in grams?

Concentrated $HCl$ is $10 \,N$. How can $1000 \,cc$ of $1 \,N \,HCl$ be prepared by dilution?

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)

$25.3 \ g$ of sodium carbonate,$Na_2CO_3$ is dissolved in enough water to make $250 \ mL$ of solution. If sodium carbonate dissociates completely,the molar concentration of sodium ions,$Na^{+}$,and carbonate ions,$CO_3^{2-}$,are respectively:
(Molar mass of $Na_2CO_3 = 106 \ g \ mol^{-1}$)