Basic chemistry competencies

Darllenwch drwy’r gymraeg

The worksheets have ten questions per topic and are available as word documents, so can be adapted to suit your lesson. The topics covered in these Starters for ten are: balancing equations, constructing ionic formulae and writing equations from text. 

Example questions

For each of the following ionic salts, determine the cation and anion present and use these to construct the formula of the salt.

(5 marks)

1. Magnesium oxide
2. Sodium sulfate
3. Calcium hydroxide
4. Aluminium oxide
5. Copper(I) oxide

When an acid is added to water it dissociates to form H⁺ ions (which make it acidic) and an anion. These acidic hydrogen atoms can be used to determine the charge on the anion.

Deduce the charge on the anions in the following acids. The acidic H atoms, H⁺, have been underlined for you.

(5 marks)

1. H₂SO₃
2. HNO₃
3. H₃PO₄
4. HCOOH
5. H₂CO₃

The following questions contain a written description of a reaction. In some cases the products may be missing as you will be expected to predict the product using your prior knowledge.

For more advanced equations you may be given some of the formula you need.

For each one, write a balanced symbol equation for the process.

(10 marks)

1. The reaction between silicon and nitrogen to form silicon nitride Si₃N₄.
2. The neutralisation of sulfuric acid with sodium hydroxide.
3. The preparation of boron trichloride from its elements.
4. The reaction of nitrogen and oxygen to form nitrogen monoxide.
5. The combustion of ethanol (C₂H₅OH) to form carbon dioxide and water only.
6. The formation of silicon tetrachloride (SiCl₄) from SiO₂ using chlorine gas and carbon.
7. The extraction of iron from iron(III) oxide (Fe₂O₃) using carbon monoxide.
8. The complete combustion of methane.
9. The formation of one molecule of ClF₃ from chlorine and fluorine molecules.
10. The reaction of nitrogen dioxide with water and oxygen to form nitric acid.

Notes

Full question and answer sheets are available from the ‘Downloads’ section below, with editable versions available.