Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Inorganic Chemistry
869 practice questions
Topics covered
- The Alkali Metals85 practice questions
- The Halogens86 practice questions
- Gases in the Atmosphere86 practice questions
- Reactivity Series163 practice questions
- Extraction and Uses of Metals128 practice questions
- Acids, Alkalis and Titrations83 practice questions
- Acids, Bases and Salt Preparations156 practice questions
- Chemical Tests68 practice questions
Practice questions
11–20 of 374 · Normal
Question 11
3 marks · Normal
Answer and see the solution →Lithium (Li), sodium (Na), and potassium (K) are all Group 1 metals. Each loses its single outer electron in reactions. The number of protons in lithium is 3, in sodium is 11, and in potassium is 19.
Calculate the number of electron shells in an atom of potassium and explain how this relates to its reactivity compared to sodium.
Question 12
3 marks · Normal
Answer and see the solution →When potassium and sodium are each added separately to water, potassium reacts much more vigorously than sodium.
Use knowledge of their atomic structures to explain fully why potassium is more reactive than sodium.
Question 13
4 marks · Normal
Answer and see the solution →The table shows the number of electron shells and the speed of reaction with water for the three Group 1 metals:
Metal Number of electron shells Relative speed of reaction (1=slow, 3=fast) Lithium 2 1 Sodium 3 2 Potassium 4 3 (a)[1 mark]Describe the pattern shown between number of electron shells and speed of reaction.
(b)[2 marks]Suggest how the electronic configuration of rubidium (Rb), the next Group 1 metal, might affect its reaction with water.
(c)[1 mark]State what you would expect the relative speed of rubidium's reaction with water to be compared to potassium.
Question 14
1 mark · Normal
Answer and check →Why does the reactivity of Group 1 elements increase as you go down the group?
- A.The outer electron becomes harder to lose because it is closer to the nucleus.
- B.More electron shells mean the outer electron is further from the nucleus and lost more easily.
- C.The atoms gain more protons so become less reactive.
- D.Atoms of Group 1 elements get lighter down the group.
Question 15
2 marks · Normal
Answer and see the solution →Explain why lithium reacts more slowly than sodium when added to water.
Question 16
4 marks · Normal
Answer and see the solution →Group 1 metals lose their outer electron in chemical reactions.
(a)[2 marks]Describe the difference in atomic structure between sodium and potassium.
(b)[2 marks]Explain how this difference affects their reactivity.
Question 17
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 18
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 19
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 20
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.