Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Acids, Alkalis and Titrations
83 practice questions
Topics covered
Practice questions
31–35 of 35 · Easy
Question 31
2 marks · Easy
Answer and see the solution →A student starts a titration with the burette reading at 3.55 cm³. When the reaction is complete, the reading is 20.00 cm³. Calculate the volume of solution added from the burette.
Question 32
5 marks · Easy
Answer and see the solution →Vinegar and household ammonia are tested using two different indicators:
(a)[1 mark]State which solution is acidic and which is alkaline.
(b)[1 mark]A drop of vinegar is placed on blue litmus paper. Describe what is observed.
(c)[2 marks]Household ammonia is tested with universal indicator. Name the colour you would expect and explain what this indicates about its pH.
(d)[1 mark]Explain how universal indicator is used to measure the pH of a solution.
Question 33
5 marks · Easy
Answer and see the solution →The table below shows the colours of three indicators in different solutions.
Indicator results for solutions A, B and C. Solution Litmus Phenolphthalein Methyl orange A Red Colourless Red B Blue Pink Yellow C Purple Colourless Yellow (a)[3 marks]Using the table, state which solution is acidic, which is alkaline, and which is neutral. Explain your answers using indicator colours.
(b)[2 marks]For solution B, state what the pH is likely to be, and justify your answer.
Question 34
5 marks · Easy
Answer and see the solution →Two solutions, X and Y, are tested:
Test results with universal indicator and methyl orange. Solution Universal indicator colour Methyl orange colour X Orange Red Y Blue Yellow (a)[2 marks]Estimate the pH value for each solution from the universal indicator colour. Show your reasoning.
(b)[2 marks]Classify each solution as strongly acidic, weakly acidic, neutral, weakly alkaline, or strongly alkaline based on your estimated pH values.
(c)[1 mark]Referring to the methyl orange results, explain whether your classifications are supported. Give reasons for your answer.
Question 35
5 marks · Easy
Answer and see the solution →A student tests a sample of rainwater using universal indicator paper. The paper turns yellow-green.
(a)[2 marks]What does the colour yellow-green indicate about the pH of the rainwater? Estimate the pH value.
(b)[1 mark]Is the rainwater acidic, neutral or alkaline? Explain your answer.
(c)[2 marks]Describe how you would use universal indicator solution, rather than paper, to measure the pH of rainwater.