Calculate the amount of water $(g)$ produced by the combustion of $16 \ g$ of methane. (in $g$)

$A$ mixture of gases contains $H_2$ and $O_2$ gases in the ratio of $1 : 4$ $(w/w)$. What is the molar ratio of the two gases in the mixture?

$A$ hydrocarbon containing $C$ and $H$ has $92.3 \% C$. When $39 \ g$ of hydrocarbon was completely burnt in $O_2$,$x$ moles of water and $y$ moles of $CO_2$ were formed. $x$ moles of water is sufficient to liberate $0.75$ moles of $H_2$ with $Na$ metal. What is the weight (in $g$) of oxygen consumed? $(C=12 \ u; H=1 \ u)$

In the bromination of propyne,$1,1,2,2-$tetrabromopropane is obtained in $27\%$ yield. The amount of $1,1,2,2-$tetrabromopropane obtained from $1 \; g$ of bromine $(Br_2)$ in this reaction is $\dots \; \times 10^{-1} \; g$. (Nearest integer)
(Molar mass: Bromine $(Br)$ $= 80 \; g/mol$)

If $1 \, L$ of $N_2$ and $7/8 \, L$ of $O_2$ gases are mixed at the same temperature and pressure,what is the relationship between their masses in the mixture?

$17.0 \ g$ of $NH_3$ completely vaporizes at $-33.42^{\circ}C$ and $1 \ bar$ pressure,and the enthalpy change in the process is $23.4 \ kJ \ mol^{-1}$. The enthalpy change for the vaporization of $85 \ g$ of $NH_3$ under the same conditions is $..... \ kJ$.