Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
pH and indicators
19 practice questions
Practice questions
1–10 of 19
Question 1
1 mark · Easy
Answer and see the solution →State what colour phenolphthalein turns in an acidic solution.
Question 2
3 marks · Easy
Answer and see the solution →Classify each solution by its pH.
(a)[1 mark]A solution has a pH of 2. State whether it is strongly acidic, weakly acidic, neutral, weakly alkaline, or strongly alkaline.
(b)[1 mark]A solution has a pH of 9. What type of solution is this according to the pH scale?
(c)[1 mark]A solution has a pH of 7. What type of solution is this?
Question 3
2 marks · Easy
Answer and see the solution →A student tests two solutions with litmus paper. Solution X turns blue litmus red. Solution Y turns red litmus blue. How many solutions are acidic?
Question 4
2 marks · Easy
Answer and see the solution →Explain why a solution with a pH of 5 is not considered strongly acidic. Include information about the pH scale in your answer.
Question 5
3 marks · Easy
Answer and see the solution →Results of adding indicators to three unknown solutions. Solution Litmus (colour) Methyl orange (colour) Phenolphthalein (colour) A red red colourless B blue yellow pink C blue yellow colourless Use the table to answer the following questions about solutions A, B, and C.
(a)[1 mark]Which solution is acidic?
(b)[1 mark]Which solution is alkaline?
(c)[1 mark]Which indicator could you use to distinguish solutions B and C? State the colour it would show for each.
Question 6
1 mark · Easy
Answer and see the solution →State the pH value of a neutral solution.
Question 7
3 marks · Easy
Answer and see the solution →Some students are testing three household substances with universal indicator.
(a)[1 mark]Explain what universal indicator does when added to an aqueous solution.
(b)[1 mark]A solution turns orange with universal indicator. State if this solution is acidic, neutral or alkaline.
(c)[1 mark]Which household substance is likely to give a universal indicator colour of purple? Choose from: vinegar, tap water, sodium bicarbonate solution, bleach.
Question 8
2 marks · Easy
Answer and see the solution →A solution has a pH of 10. How many whole numbers above the neutral pH is this solution? Show your working.
Question 9
2 marks · Normal
Answer and see the solution →State the colour change observed when litmus paper is placed in (a) an acidic solution and (b) an alkaline solution.
(a)[1 mark]Colour of litmus paper in an acidic solution:
(b)[1 mark]Colour of litmus paper in an alkaline solution:
Question 10
4 marks · Normal
Answer and see the solution →The table below shows the pH values of four different aqueous solutions.
Solution pH P 2 Q 5 R 8 S 13 (a)[1 mark]State which solution is strongly acidic.
(b)[1 mark]State which solution is neutral.
(c)[1 mark]State which solution is weakly alkaline.
(d)[1 mark]State which solution is strongly alkaline.