Aluminum chloride ionizes in aqueous solution because ........

$10 \ mL$ of $2 \ M$ $NaOH$ solution is added to $20 \ mL$ of $1 \ M$ $HCl$ solution kept in a beaker. Now,$10 \ mL$ of this mixture is poured into a volumetric flask of $100 \ mL$ containing $2 \ moles$ of $HCl$ and made the volume up to the mark with distilled water. The solution in this flask is $:$

Which of the following substances represents calcium chlorite?

$4 \ g$ equimolar mixture of $NaOH$ and $Na_{2}CO_{3}$ contains $x \ g$ of $NaOH$ and $y \ g$ of $Na_{2}CO_{3}$. The value of $x$ is $..... \ g$. (Nearest integer)

Ferric alum has the composition $(NH_4)_2SO_4 \cdot Fe_2(SO_4)_3 \cdot xH_2O$,where $x$ is..........

$250 \, mL$,$6 \, M$ $HCl$ and $350 \, mL$,$8 \, M$ $HNO_3$ are mixed with water to make the strength of the resulting solution $3 \, N$. What is the volume of water added? $mL$