Test on Neutralization Reactions and pH

Question 1: Adding an alkali to spilled concentrated acid makes it safe to be mopped up.

A. Ano

B. Ne

Explanation: The study materials state that alkalis cancel out acids, making them more neutral, and this process is called neutralisation. This principle applies to making spilled concentrated acid safe by neutralising it with an alkali.

Question 2: Ammonium nitrate fertiliser is produced by combining ammonium sulfate and nitric acid.

A. Ano

B. Ne

Explanation: Ammonium nitrate fertiliser is a salt made using ammonium hydroxide and nitric acid.

Question 3: According to the study materials, what observation indicates that a neutral solution has been achieved when performing neutralisation using universal indicator?

A. The solution turns red, indicating high acidity.

B. The pH of the solution reaches 7.

C. The solution becomes cloudy.

D. The solution turns a precise colour that indicates neutrality.

Explanation: The study materials state that 'As sodium hydroxide is added, the pH increases until it reaches 7. The solution is neutral at this point.' This directly indicates that a pH of 7 signifies neutrality. Additionally, the materials ask 'What does the precise colour in flask X tell us?', implying that a specific colour shown by the universal indicator is used to identify neutrality, as the indicator measures pH, and neutrality is defined by a pH of 7.

Question 4: Which of the following salts is produced when nitric acid is involved in a neutralisation reaction?

A. Lithium chloride

B. Sodium sulfate

C. Potassium nitrate

D. Sodium chloride

Explanation: The study materials state that 'Nitric acid produces nitrate salts'. Among the given options, Potassium nitrate is a nitrate salt, specifically mentioned as an example of a salt produced by neutralisation.

Question 5: Sulfuric acid removes rust (iron oxide) from iron and steel objects through a neutralisation reaction.

A. Ano

B. Ne

Explanation: The study materials explain that 'Sulfuric acid can attack the rust and remove it from the surface via a neutralisation reaction' and specify that rust is 'iron oxide'.