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:

If you have 8g of He, 4g of $H_2$, and 32g of $O_2$, which sample has the highest number of molecules?

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 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 pair of gases contain the same number of molecules?

The number of moles in 11.2 L at STP of oxygen

Upon treating a mixture of $0.46$ g of formic acid and $0.9$ g of oxalic acid with concentrated $H_2SO_4$, a gaseous mixture is evolved. This mixture is then passed through pellets of $KOH$. Determine the mass (in g) of the remaining product at STP.

Suppose the elements X and Y combine to form two compounds $X{Y_2}$ and ${X_3}{Y_2}$. When 0.1 mole of $X{Y_2}$ weights 10 g and 0.05 mole of ${X_3}{Y_2}$ weights 9 g, the atomic weights of X and Y are

Weight of $112\,\,mL$ of oxygen at NTP on liquification would be:

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

If you have samples of 0.5 moles of water, 36 g of water, and 3.011 x 10²³ molecules of water, which sample has the greatest mass?