Homework Practice

Printable assignment

Acids, Bases and Salts: Neutralisation in Real Life

Neutralisation Around Us

Question 1mcq

A person has acidity due to excess acid in the stomach. Why can an antacid help?

A.It adds more acid to the stomach.

B.It turns acid into oxygen gas only.

C.It contains a mild base that neutralises excess acid.

D.It stops all digestion permanently.

Question 2mcq

After an ant sting, a teacher suggests applying a mild baking soda paste. What idea explains this?

A.A strong acid should be added to every sting.

B.Baking soda removes oxygen from air.

C.The sting becomes a physical change only.

D.A mild base can neutralise the acidic sting.

Question 3mcq

In the reaction hydrochloric acid + sodium hydroxide

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sodium chloride + water, sodium chloride is the:

A.Salt

B.Acid

C.Base

D.Indicator

Question 4mcq

Which is the safest practice while testing an unknown solution with litmus?

A.Taste it to check if it is sour.

B.Use a dropper or glass rod and avoid touching or tasting the solution.

C.Smell it deeply before testing.

D.Mix it with all available chemicals.

Question 5mcq

Unknown solution P turns blue litmus red. Unknown solution Q turns red litmus blue. What happens if suitable amounts of P and Q are mixed?

A.Both must become stronger acids.

B.Both must remain unchanged because indicators are used.

C.They may neutralise each other to form salt and water.

D.They must produce wool fibres.

Reasoning and Safety

Question 6mcq

A farmer’s soil is too acidic for a crop. Which treatment is most scientifically suitable?

A.Add more acid to make it fertile.

B.Pour concentrated acid directly.

C.Remove all water from the soil.

D.Add a basic substance such as lime in a controlled amount.

Question 7mcq

Which statement about salts is correct at this level?

A.A salt can be formed when an acid and a base neutralise each other.

B.Every salt is sour and turns blue litmus red.

C.Salts are always used only for eating.

D.A salt is the same thing as an indicator.

Question 8mcq

Why should concentrated acids and bases not be handled casually in a school lab?

A.They are always harmless because they are liquids.

B.They can be corrosive and damage skin, eyes or materials.

C.They become food when touched.

D.They cannot react with anything.

Question 9mcq

A student says, “If blue litmus does not change, the solution must be neutral.” What is the best correction?

A.The statement is always correct.

B.Blue litmus can test only temperature.

C.Test red litmus too, because a base also does not change blue litmus.

D.Red litmus and blue litmus always give the same result.

Question 10mcq

China rose indicator turns a solution dark pink/magenta. Another sample turns it green. What can a student reasonably infer?

A.Both samples are definitely pure water.

B.The colour change is unrelated to the solution.

C.China rose can measure only mass.

D.The samples have different acidic/basic nature.