Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
The Alkali Metals
85 practice questions
Topics covered
Practice questions
21–30 of 36 · Easy
Question 21
1 mark · Easy
Answer and see the solution →State the usual colour of potassium bromide crystals.
Question 22
3 marks · Easy
Answer and see the solution →Describe what you would observe and name the product when sodium is heated strongly in air.
(a)[1 mark]State the colour of the flame when sodium burns.
(b)[1 mark]What is the appearance of the solid product formed?
(c)[1 mark]Name the compound produced in this reaction.
Question 23
2 marks · Easy
Answer and see the solution →A student heats a piece of potassium weighing 3.9 g in air. Potassium reacts fully to form potassium oxide (K$_2$O) according to the equation:
Calculate the maximum mass of potassium oxide formed from 3.9 g of potassium. (Relative atomic masses: K = 39, O = 16)
Question 24
2 marks · Easy
Answer and see the solution →A student dissolves 5.1 g of sodium chloride in water. Sodium chloride is a typical Group 1 metal compound. (Relative atomic masses: Na = 23, Cl = 35.5)
Calculate the number of moles of sodium chloride dissolved.
Question 25
1 mark · Easy
Answer and see the solution →State the symbol of francium.
Question 26
3 marks · Easy
Answer and see the solution →Francium is below caesium in Group 1 of the Periodic Table.
(a)[1 mark]State whether francium is expected to be hard or soft.
(b)[1 mark]State if francium is expected to react faster or slower with water compared to caesium.
(c)[1 mark]State the colour francium is predicted to be when freshly cut.
Question 27
2 marks · Easy
Answer and see the solution →The density of caesium is 1.87 g/cm³. Based on the trend in Group 1, predict the approximate density of francium. Give your answer to one decimal place.
Question 28
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 29
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 30
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.