$A$ mixture of sodium oxide $(Na_2O)$ and calcium oxide $(CaO)$ is dissolved in water and saturated with excess carbon dioxide $(CO_2)$ gas. The resulting solution is $......$ It contains $.........$ :

Chlorophyll extracted from the crushed green leaves was dissolved in water to make $2 \, L$ solution of $Mg$ of concentration $48 \, ppm$. The number of atoms of $Mg$ in this solution is $x \times 10^{20}$ atoms. The value of $x$ is (Nearest Integer) (Given : Atomic mass of $Mg$ is $24 \, g \, mol^{-1}$,$N_{A} = 6.02 \times 10^{23} \, mol^{-1}$)

Identify the type of reaction for the following chemical equation:
$CuSO_4 + 2NaOH (excess) \longrightarrow Cu(OH)_2 \downarrow + Na_2SO_4$

What is $Rasavidya$?

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$2AgF + MgCl_2 \longrightarrow MgF_2 \downarrow + 2AgCl \downarrow$

When $400 \ mL$ of $0.2 \ M \ H_2SO_4$ is mixed with $600 \ mL$ of $0.1 \ M \ NaOH$, the heat evolved is $3.43 \ kJ$. If the specific heat of water is $4.18 \ J \ K^{-1} \ g^{-1}$, the rise in temperature of the final solution will be ........... $K$. (Assume the specific heat capacity of the final solution is the same as that of water)