How many grams of $Cu(NO_3)_2$ are needed to obtain $1 \ g$ of copper? $($ Atomic mass: $Cu = 63.5, N = 14, O = 16$ $)$

The volume of $0.05 \, M$ $H_2SO_4$ required to neutralize $80 \, mL$ of $0.13 \, N$ $NaOH$ will be ...... $mL$.

Calculate the concentration of nitric acid in moles per litre in a sample which has a density of $1.41 \, g \, mL^{-1}$ and the mass percent of nitric acid in it is $69 \%$.

At $400 \ K$,$1 \ mol$ of a hydrocarbon is completely burned. It produces $132 \ g$ of a gas along with $72 \ g$ of water vapour. The hydrocarbon is:

$5 \ g$ of zinc is treated separately with an excess of
$(a)$ dilute hydrochloric acid and
$(b)$ aqueous sodium hydroxide.
The ratio of the volumes of $H_{2}$ evolved in these two reactions is:

$x \ mg$ of pure $HCl$ was used to make an aqueous solution. $25.0 \ mL$ of $0.1 \ M$ $Ba(OH)_2$ solution is used when the $HCl$ solution was titrated against it. The numerical value of $x$ is . . . . . . $\times 10^{-1}$. (Nearest integer)
Given: Molar mass of $HCl$ and $Ba(OH)_2$ are $36.5$ and $171.0 \ g \ mol^{-1}$ respectively.