One and a half mole of oxygen combine with aluminium to form $Al_2O_3$. The weight of aluminium metal used in this reaction is .............. $g$ (Atomic weight of $Al = 27$).

Equal weights of ethane and hydrogen are mixed in an empty container at $25^{\circ} C$. The fraction of total pressure exerted by hydrogen is

$23 \ g$ of $Na$ will react with methyl alcohol to give:

The molarity of $0.2 \ N$ $Na_2CO_3$ solution will be (in $M$)

In the reaction shown,$5 \ g$ of toluene is converted into benzaldehyde with $92 \%$ yield. The amount of benzaldehyde produced is $.... \times 10^{-2} \ g$. (Nearest integer)

The right option for the mass of $CO_2$ produced by heating $20 \ g$ of $20 \%$ pure limestone is $........ \ g$ (Atomic mass of $Ca = 40$) $[CaCO_3 \stackrel{1200 \ K}{\longrightarrow} CaO + CO_2]$