Sunday, June 26, 2022

The Mole




















 Prep


1.       Calculate the number of elementary entitles (atoms or molecules) in 3.0 mol of a substance.

2.       Suggest why one mole of silicon has a different mass from one mole of aluminium.

3.       Calculate the number of moles there are in a substance containing:

2.0 × 1024 molecules ;                     1.5 × 1017 atoms ;             2.0 × 1024 molecules.

4.       The molar mass of copper is 64 g mol–1 calculate the number of atoms in copper

of mass 1.0 kg.

5.       The molar mass of uranium is 235 g mol–1. Calculate the mass of a single atom of uranium.

6.       The density of lead is 11340 kgm−3. Each lead atom has a mass of 3.46 × 10−25 kg. Calculate the number of moles of lead in a lead block with a volume of 0.20 m3.

7.       Calculate the mass of 4.0 mol of helium-4 gas.

8.       Calculate the molar mass of methane (CH4).

9.       Calculate the number of molecules in 50 g of carbon dioxide.