The density of a liquid is $1.5 \, g/mL$. There are $50 \, drops$ in $5 \, mL$. The number of molecules in $1 \, drop$ is (molecular weight of liquid is $100$).

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

The more commonly used baking powder contains about $30\%$ $NaHCO_3$,$20\%$ $NaAl(SO_4)_2$,$10\%$ $Ca(H_2PO_4)_2$ and $40\%$ starch. Which of the following statements is/are correct?

Equal weights of $CH_{4}$ and $H_{2}$ are mixed in an empty container at $25^{\circ} C$. The fraction of the total pressure exerted by $H_{2}$ is

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 $24 \, g \, mol^{-1}$,$N_{A} = 6.02 \times 10^{23} \, mol^{-1}$)

Nitrogen atom has an atomic number of $7$ and oxygen has an atomic number of $8$. The total number of electrons in a nitrate ion $(NO_3^-)$ will be: