When a jar containing a gaseous mixture of equal volumes of $CO_2$ and $H_2$ is placed in a solution of sodium hydroxide,the solution level will:

Which of the following has the minimum number of oxygen atoms?

The volume of $HCl$,containing $73 \ g \ L^{-1}$,required to completely neutralize $NaOH$ obtained by reacting $0.69 \ g$ of metallic sodium with water,is $........ mL$. (Nearest Integer) (Given: molar masses of $Na, Cl, O, H$ are $23, 35.5, 16$ and $1 \ g \ mol^{-1}$ respectively)

Which of the following statements is incorrect for the compound $A_xB_y$?

Rearrange the following ($I$ to $IV$) in the order of increasing masses:
$(I)$ $0.5$ mole of $O_3$
$(II)$ $0.5 \, g$ atom of oxygen
$(III)$ $3.011 \times 10^{23}$ molecules of $O_2$
$(IV)$ $5.6 \, L$ of $CO_2$ at $STP$

How is concentrated $H_2SO_4$ diluted?