If one liter of air is repeatedly passed over heated copper and magnesium until no further reduction in volume occurs,the final volume of the air will be approximately ......... $mL$.

$100 \ g$ of a mixture of $NaOH$ and $Na_2SO_4$ is neutralized by $100 \ mL$ of $0.5 \ M \ H_2SO_4$. What is the amount of $Na_2SO_4$ present in the mixture (in $g$)?

Air contains $23\% \, O_2$ and $77\% \, N_2$ by weight. What is the percentage of $O_2$ by volume?

Which of the following aqueous solutions is neutral?

An athlete is given $100 \ g$ of glucose $(C_6H_{12}O_6)$ for energy. This is equivalent to $1800 \ kJ$ of energy. The $50 \ \%$ of this energy gained is utilized by the athlete for sports activities at the event. In order to avoid storage of energy,the weight of extra water he would need to perspire is $......... \ g$ (Nearest integer).
Assume that there is no other way of consuming stored energy. Given: The enthalpy of evaporation of water is $45 \ kJ \ mol^{-1}$.
Molar mass of $C, H$ and $O$ are $12, 1$ and $16 \ g \ mol^{-1}$.

State whether the following statements are true or false:
$(i)$ $^\circ F = \frac{9}{5} (^circ C) + 32$
$(ii)$ In $1808$,Dalton published the law of chemical combination in the journal "New System of Chemical Philosophy".
$(iii)$ If the molar mass of a dibasic acid is $100$,its equivalent mass is $200$.