In a mixture of $1 \ g$ of $H_2$ and $8 \ g$ of $O_2$,the mole fraction of hydrogen is

In how many grams of $CO_2$ is the number of $C$ atoms equal to $1.3699 \times 10^{23}$?

Find the number of molecules,number of carbon atoms,number of hydrogen atoms,and total number of atoms in $5.6 \ L$ of $CH_4$ at $STP$.

The largest number of molecules is in

$7.0 \, g$ of $N_2$,$8.0 \, g$ of $O_2$,and $34.0 \, g$ of $NH_3$ are present in a $1 \, L$ vessel. The active masses in $mol \, L^{-1}$ are respectively:

If $10^{20}$ grains are distributed in one second,then the time taken to distribute an Avogadro number of grains is ........ hours.