Question 3.3

Question

Study the investigative setup below and answer the questions that follow.
16

Question 3.3.1 [2 marks]
Write an investigative question for this investigation.
Question 3.3.2 [2 marks]
Write a suitable hypothesis for this investigation.
Question 3.3.3 [2 marks]
What does the soda-lime and sodium hydroxide do?
Question 3.3.4 [1 mark]
Which test tube is considered the control of the investigation? Question 3.3.5 [2 marks]
What happened to the lime water in test tube D? Why did this happen?
[9 mark

Answer 1

Question 3.3.1: How does the presence of soda-lime and sodium hydroxide affect the pH of a solution?

Question 3.3.2: If soda-lime and sodium hydroxide are added to a solution, then the pH of the solution will increase.

Question 3.3.3: The soda-lime and sodium hydroxide are likely used in this investigation to either absorb acidic gases or neutralize acidic solutions.

Question 3.3.4: Test tube A is considered the control of the investigation as it does not contain any added soda-lime or sodium hydroxide.

Question 3.3.5: The lime water in test tube D turned milky, indicating the presence of carbon dioxide. This happened because the carbon dioxide in the air reacted with the calcium hydroxide in the lime water to form calcium carbonate, which is insoluble and creates a milky appearance.