Part 1 – Introduction to Unit 1
1. Which box (or boxes) in the grid below shows:
(a) something that always happens in a chemical reaction (2 boxes)
(b) an example of an everyday chemical reaction (1 box)
2. In a table, divide the following list of substances into 2 groups: elements and compounds.
magnesium, iron, water, hydrogen, carbon dioxide, sodium chloride, nitrogen dioxide, lead
3.
(a) Which two boxes show (i) elements only (ii) a 2 element compound
(b) Which one box shows (i) a 3 element compound (ii) a mixture
4. When the following elements react, name the compound they form:
(a) iron and sulphur (b) magnesium and chlorine
(c) zinc, sulphur and oxygen (d) lead, carbon and oxygen
5. Which elements are found in:
(a) aluminium sulphide (b) magnesium nitrate (c) hydrogen chloride
(d) lithium sulphate (e) calcium hydroxide (f) silicon oxide
6. If a copper and sulphur mixture is heated, a red glow is seen to spread through the mixture and this continues even when the heating has stopped. A black solid remains at the end.
(a)What is the difference between a mixture and a compound?
(b)Give 2 pieces of evidence that suggest that a chemical reaction has taken place.
(c)Name the black solid. Is it an element or a compound?
7. Jennifer makes a salt solution by dissolving salt in water.
(a)Which substance is the solute and which is the solvent?
(b)What could she add to the solution to make it (i) more dilute? (ii) more concentrated?
8. Vinegar can be made by dissolving ethanoic acid in water. Use a diagram to show how this could be done and label the solute, solvent and solution.
9. Sulphuric acid is one of the world’s most important chemical compounds. This bar chart shows the uses of sulphuric acid in this country.
(a) What is most sulphuric acid used to make?
(b) What % of sulphuric acid is used to make detergents?
