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PH scale test with answers for grade 8 science (free PDF download)

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Quick answer: Acids have a pH below 7, alkalis have a pH above 7, and a neutral liquid such as pure water has a pH of exactly 7. This grade 8 science test on pH scale has 8 questions worth 20 marks, to do in 45 minutes: indicators, reading the scale and dilution by 100. The mark scheme is on a separate page; free printable PDF.

PH scale test with answers for grade 8 science (free PDF download)

Also, this grade 8 science test on pH scale test works like a real class test. Then, the mark scheme is on a separate page, so revise with the lesson first.

Also, this test lasts 45 minutes and is worth 20 marks. Answer every question, show your working for calculations and give units. In addition, use the key facts from the lesson, and write full sentences for explanations.

Level: Grade 8 science (Year 9 · Class 8) · Curriculum: MS-PS1-2

PH scale test: the test questions

Time: 45 minutes · 8 questions · Total: 20 marks · Calculator allowed

Question 1 Indicators (2 marks)

  1. State the colour of blue litmus paper in an acid. (1 mark)
  2. Afterwards, state the colour of universal indicator in a neutral liquid. (1 mark)

Question 2 Reading the scale (3 marks)

In addition, the scale shows the pH of four liquids P, Q, R and S.

A black and white pH scale from 0 to 14 with four marked liquids: P at pH 1, Q at pH 6, R at pH 7 and S at pH 1201234567891011121314PQRS
pH values of four liquids.
  1. Moreover, identify the neutral liquid. (1 mark)
  2. Identify the strongest acid. (1 mark)
  3. Also, identify the liquid that turns universal indicator purple. (1 mark)

Question 3 Dilution by 100 (2 marks)

A strong acid of pH 3 is diluted by a factor of 100.

  1. Then, calculate the new pH. (2 marks)

Question 4 Comparing acidity (3 marks)

Then, liquid X has pH 3 and liquid Y has pH 6.

  1. Calculate how many times more acidic X is than Y. (2 marks)
  2. In addition, state what both liquids are. (1 mark)

Question 5 Why not alkaline? (3 marks)

  1. Moreover, explain why adding more and more water to an acid never gives an alkali. (3 marks)

Question 6 Safe working (2 marks)

  1. State two safety rules when diluting a concentrated acid. (2 marks)

Question 7 Neutralisation (2 marks)

  1. Afterwards, write the word equation for hydrochloric acid reacting with sodium hydroxide. (2 marks)

Question 8 Dilution plan (3 marks)

Imani in Kampala has 40 mL of strong acid of pH 1 and wants pH 3.

  1. Calculate the dilution factor. (1 mark)
  2. Moreover, calculate the final volume. (1 mark)
  3. Calculate the volume of water to add. (1 mark)

See the pH scale test answers and mark scheme

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