Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Compounds of the alkali metals
19 practice questions
Practice questions
1–8 of 8 · Normal
Question 1
2 marks · Normal
Answer and see the solution →Describe what you would observe when freshly cut pieces of sodium and potassium are exposed to air.
Question 2
4 marks · Normal
Answer and see the solution →The compounds of lithium, sodium, and potassium often appear similar.
(a)[1 mark]State the usual colours of lithium chloride, sodium chloride, and potassium chloride.
(b)[1 mark]Explain why solutions of these compounds are colourless.
(c)[1 mark]State their typical solubility in water.
(d)[1 mark]Give the formula for each of the following: (i) sodium oxide (ii) potassium oxide
Question 3
3 marks · Normal
Answer and see the solution →Most group 1 metal compounds are described as colourless or white and are soluble in water.
(a)[2 marks]Explain why compounds of lithium, sodium, and potassium with colourless anions appear colourless or white.
(b)[1 mark]Suggest why potassium permanganate(VII) solution is purple while sodium chloride solution is colourless.
Question 4
4 marks · Normal
Answer and see the solution →Three students set up an experiment to observe how quickly different alkali metals react with air. Each student cut a fresh piece of either lithium, sodium, or potassium, put it onto a clean white tile, and timed how long it took to lose its shiny appearance (tarnish). The results:
Time for shiny appearance to disappear after cutting (room temperature, seconds) Metal Time (s) Lithium 65 Sodium 24 Potassium 8 (a)[1 mark]Complete the following order of reactivity of the metals with air, from least to most reactive:
________ < ________ < ________
(b)[2 marks]Use the data to explain your answer to part (a).
(c)[1 mark]State the white solid formed when sodium reacts with oxygen in air.
Question 5
1 mark · Normal
Answer and check →Which compound is most likely to form a colourless solution in water?
- A.Potassium chloride
- B.Copper(II) sulphate
- C.Iron(III) nitrate
- D.Nickel(II) chloride
Question 6
2 marks · Normal
Answer and see the solution →State the formula and appearance of the solid produced when lithium burns in air.
Question 7
4 marks · Normal
Answer and see the solution →Group 1 compounds tend to dissolve easily in water.
(a)[1 mark]Describe what would be seen when sodium nitrate is dissolved in water.
(b)[2 marks]Explain why the solution formed is colourless.
(c)[1 mark]State an example of a group 1 compound that is not white or colourless, and give the reason for its colour.
Question 8
3 marks · Normal
Answer and see the solution →A student places a piece of sodium metal weighing 2.3 g in air and leaves it to react until it forms a layer of sodium oxide. The equation for the reaction is:
Calculate the mass of sodium oxide formed from 2.3 g of sodium, assuming all of the sodium reacts completely. (Relative atomic masses: Na = 23, O = 16)