Calculations quiz

1. What is the empirical formula of a compound in which 0.48 g of carbon combines with 0.08 g of hydrogen and 0.64 g of oxygen?

2. To determine the formula of a metal oxide by combustion, magnesium is heated in a crucible. Why is the crucible is cooled, weighed, reheated, cooled, re-weighed, and so on?

3. 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.

4. State the particles that are found within the nucleus of an atom

5. Calculate the relative formula mass(Mr) of hydrated copper (II) sulfate (CuSO₄.5H₂O)

6. A sample of carbon contained 98.90% carbon-12 and 1.10% carbon-13. Calculate the relative atomic mass of carbon

7. How many electron shells do the elements in the third period have?

8. What is the atomic number of a chlorine atom?

9. What is meant by the term empirical formula?