IB Chemistry S1.4 Counting Particles by Mass: the Mole Questionbank

What is the number of atoms in 1.00 mol of helium gas?

A marine biologist studies the effect of ocean acidification on calcium carbonate shells. In the lab, she reacts powdered $\mathrm{CaCO_3}$ with excess hydrochloric acid and collects the carbon dioxide gas evolved. The reaction is:

$\mathrm{C}\mathrm{a}\mathrm{C}{\mathrm{O}}_3(\mathrm{s})+2\mathrm{H}\mathrm{C}\mathrm{l}(\mathrm{a}\mathrm{q})\to \mathrm{C}\mathrm{a}\mathrm{C}{\mathrm{l}}_2(\mathrm{a}\mathrm{q})+{\mathrm{H}}_2\mathrm{O}(\mathrm{l})+$

A 1.00 g sample of a metal $M$ reacts with excess oxygen to form 1.27 g of the oxide $M_2O$. What is the relative atomic mass ($$) of ?

Which unit is commonly used for molar mass?

How many molecules are there in 2.00 mol of carbon dioxide? (Use Avogadro’s constant from the IB Chemistry data booklet.)