The number of moles of hydrogen molecules required to produce 20 moles of ammonia through Haber’s process is:

A 0.50 $M$ solution of $KI$ reacts with excess of ${{\rm{H}}_2}{\rm{S}}{{\rm{O}}_4}$ and ${\rm{KI}}{{\rm{O}}_3}$ solutions according to the equation, $6{{\rm{H}}^ + } + 5{{\rm{I}}^ - } + {\rm{IO}}_3^ - o 3{{\rm{I}}_2} + 3{{\rm{H}}_2}{\rm{O}}$. Which of the following statements is true?

A 20 L vessel contains 0.1 mole of $O_2$ at 300 K. $O_3$ is prepared in the vessel by subjecting $O_2$ to silent electric discharge till the volume is reduced to 15 L at 300K. What is the number of moles of $O_3$ formed?

A mixture of $1.2$ g formic acid and $2.25$ g oxalic acid is treated with conc. $H_2SO_4$. The evolved gaseous mixture is passed through $KOH$ pellets. Calculate the mass (in g) of the remaining product at STP.

The number of Na atoms in 46 g ‘Na”

Elements X and Y form compounds $XY_2$ and $X_3Y_2$. If 20 g of $XY_2$ contains 0.2 moles and 18 g of $X_3Y_2$ contains 0.1 moles. What are the atomic weights of elements X and Y?

If Avogadro number, $N_A$, is changed from $6.022 imes 10^{23} \, mol^{-1}$ to $6.022 imes 10^{20} \, mol^{-1}$, this would change:

Which of the following has the maximum number of atoms?

If 1 mole of a substance contains $6.022 imes 10^{23}$ particles, how many particles are present in 0.5 moles?

What is the mass of one mole of carbon dioxide (CO2)?

The isoelectronic species among the following are:$I){\rm{CH}}_3^ + ;{\rm{II)NH}}_2^ + ;{\rm{III)NH}}_4^ + ;{\rm{IV)N}}{{\rm{H}}_3}$