Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
The Alkali Metals
85 practice questions
Topics covered
Practice questions
61–70 of 85
Question 61
2 marks · Easy
Answer and see the solution →Francium is predicted to react very violently with water. Explain using trends in Group 1 why francium is expected to be even more reactive than caesium.
Question 62
3 marks · Easy
Answer and see the solution →Table 1 shows the melting points of some alkali metals.
Table 1: Melting points of alkali metals Element Melting point / °C Lithium 180.5 Sodium 97.8 Potassium 63.5 Rubidium 39.3 Caesium 28.5 (a)[1 mark]Describe the trend in melting points as you go down Group 1.
(b)[1 mark]Use the trend to estimate the melting point of francium.
(c)[1 mark]Francium's predicted melting point is below room temperature in a warm country. What state (solid, liquid or gas) might it be in during a hot day?
Question 63
3 marks · Easy
Answer and see the solution →Francium is expected to react rapidly when exposed to air or water.
(a)[1 mark]State what would happen to francium's shiny surface if a small piece was exposed to air.
(b)[1 mark]Predict one observation you would expect if francium was added to water.
(c)[1 mark]Name the gas produced in the reaction between francium and water.
Question 64
2 marks · Easy
Answer and see the solution →Room temperature is about 25°C. If francium has a melting point of 22°C, what state (solid or liquid) would you expect francium to be in at room temperature? Explain your answer with a calculation.
Question 65
1 mark · Easy
Answer and see the solution →State one physical property that francium is predicted to have, based on trends in Group 1 of the Periodic Table.
Question 66
2 marks · Normal
Answer and see the solution →State two physical properties you would expect francium to have, based on its position in Group 1 of the Periodic Table.
Question 67
4 marks · Normal
Answer and see the solution →Francium has never been seen, but chemists can predict its properties using trends in Group 1. Answer the following about francium.
(a)[1 mark]State the formula of the hydroxide formed when francium reacts with water.
(b)[2 marks]Describe what you would observe when a piece of francium is added to water.
(c)[1 mark]Explain why francium reacts more violently with water than potassium.
Question 68
3 marks · Normal
Answer and see the solution →The melting point of alkali metals decreases as you move down the group:
Melting points of Group 1 elements Element Atomic number Melting point / °C Lithium 3 181 Sodium 11 98 Potassium 19 64 Rubidium 37 39 Caesium 55 29 Francium 87 ? Use the trend shown in the table to estimate a value for the melting point of francium.
Question 69
3 marks · Normal
Answer and see the solution →Explain why francium compounds are expected to be colourless and soluble in water.
Question 70
4 marks · Normal
Answer and see the solution →The graph below shows the melting points of some alkali metals against their atomic numbers.
Melting points of alkali metals (a)[1 mark]Describe the trend shown by the graph.
(b)[1 mark]Estimate the melting point of francium (atomic number 87) using the graph.
(c)[2 marks]Explain how you used the data to make your estimate.