Which of the following contains the maximum number of water molecules?

What is the number of atoms present in 1 mole of oxygen gas?

A mixture of $CaCO_3$ and $MgCO_3$ weighing 1.84 g on heating leaves a residue weighing 0.96 g. If the percentage by mass of $CaCO_3$ in the original mixture is x%, what is the value of x/2?

Which of the following has the largest number of atoms?

A sample of magnesium carbonate weighing 30.0 g is heated until it completely decomposes to magnesium oxide and carbon dioxide. If 12.0 g of magnesium oxide is produced, what is the percentage purity of the original magnesium carbonate sample? (Atomic weight: $Mg = 24$)

Which of the following contains the largest number of atoms?

If 10 moles of ammonia are produced via the Haber-Bosch process, how many moles of hydrogen gas were consumed?

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

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

A student heats 40.0 g of a mixture containing magnesium carbonate and some inert impurities. Upon complete decomposition, 8.0 g of magnesium oxide is formed. Calculate the percentage by mass of magnesium carbonate in the original mixture. (Atomic weight: $Mg = 24$)

0.3 g of an oxalate salt was dissolved in 100 mL solution. The solution required 90 mL of $N/20$ ${\rm{KMn}}{{\rm{O}}_4}$ for complete oxidation. The % of oxalate ion in salt is: