Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Acids, Alkalis and Titrations
83 practice questions
Topics covered
Practice questions
21–30 of 36 · Normal
Question 21
1 mark · Normal
Answer and check →Which of the following substances forms an alkaline solution by reacting with water to produce hydroxide ions?
- A.Sodium chloride
- B.Potassium carbonate
- C.Calcium sulfate
- D.Ethanoic acid
Question 22
2 marks · Normal
Answer and see the solution →State the formula of the ion present in all alkaline solutions and give its charge.
Question 23
4 marks · Normal
Answer and see the solution →Some cleaning products are described as 'alkaline'.
(a)[2 marks]Ammonia is commonly found in cleaning products. State the ions that are produced when ammonia reacts with water.
(b)[2 marks]Explain why solutions of ammonia are described as alkaline.
Question 24
3 marks · Normal
Answer and see the solution →A student adds hydrochloric acid (HCl), at a concentration of 0.020 mol/dm³, to water. Hydrochloric acid completely dissociates into ions:
Calculate the concentration of hydrogen ions (H⁺) in the solution after the HCl fully dissociates. Explain your reasoning.
Question 25
2 marks · Normal
Answer and see the solution →State the piece of apparatus used to measure out a precise volume of liquid in a titration, and the apparatus used to hold the liquid that is being titrated.
Question 26
4 marks · Normal
Answer and see the solution →A student wants to find out how much sodium hydroxide solution is needed to neutralise 25.0 cm³ of dilute hydrochloric acid using phenolphthalein as the indicator. Describe the main steps to carry out this titration accurately.
(a)[1 mark]State the first step to prepare the acid sample for titration.
(b)[1 mark]Describe how the student should handle the burette and indicator.
(c)[2 marks]Explain how to know when the endpoint is reached and what to do as it approaches.
Question 27
3 marks · Normal
Answer and see the solution →During a titration, a student records the following burette readings:
Titration readings Initial reading / cm³ Final reading / cm³ 4.10 21.80 Question 28
3 marks · Normal
Answer and see the solution →Explain why phenolphthalein is a better choice of indicator for an acid–alkali titration than universal indicator. Include two reasons in your answer.
Question 29
4 marks · Normal
Answer and see the solution →Look at the following table of titration results.
Titration results Titration Initial reading / cm³ Final reading / cm³ 1 1.50 23.40 2 2.20 24.10 3 1.70 23.60 (a)[2 marks]Calculate the volume of sodium hydroxide used in each titration.
(b)[1 mark]Suggest which, if any, of the three titrations should be considered an outlier. Give a reason.
(c)[1 mark]State why titrations are repeated.
Question 30
1 mark · Normal
Answer and check →In an acid-alkali titration, which piece of apparatus is used to add the alkali to the acid?
- A.Burette
- B.Measuring cylinder
- C.Pipette
- D.Test tube