Calculations quiz

1. Work out the empirical formula of an oxide of chlorine contains 7.1 g of chlorine and 1.6 g of oxygen.

2. Calculate the relative formula mass(Mr) of calcium carbonate (CaCO₃)

3. A sample of bromine contained the two isotopes in the following proportions: bromine-79 = 50.7% and bromine-81 = 49.3%. Calculate the relative atomic mass of bromine

4. How many electrons can the third shell hold?

5. What is meant by the term molecular formula?

6. State the mass and charge of a proton

7. To determine the formula of a metal oxide by combustion, magnesium is heated in a crucible. Why is a lid lifted from time to time?

8. A compound that contained 24.24% Carbon. 4.04% Hydrogen and 71.72% Chlorine and has a relative molecular mass of 99. Calculate the empirical formula and the molecular formula.

9. What is the relative atomic mass (Aᵣ) of a hydrogen atom?