Homework Practice

Printable assignment

Acids, Bases and Salts: Identify and Test Substances

Acidic, Basic or Neutral?

Question 1mcq

Riya tests four kitchen substances. Which one is most likely acidic?

A.Lemon juice

B.Soap solution

C.Baking soda solution

D.Plain distilled water

Question 2mcq

A substance feels soapy and turns red litmus blue. What is its nature?

A.Acidic

B.Basic

C.Neutral

D.Metallic

Question 3mcq

Why are indicators useful in testing acids and bases?

A.They make acids safe to drink.

B.They convert every acid into water.

C.They show a colour change in acidic or basic solutions.

D.They measure the mass of a solution.

Question 4mcq

Blue litmus paper turns red when dipped in an unknown solution. What can be concluded?

A.The solution is basic.

B.The solution is neutral.

C.The solution must be pure water.

D.The solution is acidic.

Question 5mcq

A solution changes neither red litmus nor blue litmus. Which conclusion is most reasonable?

A.It is neutral, or too weak to show a clear litmus change.

B.It is definitely a strong acid.

C.It is definitely a strong base.

D.It must be a salt crystal, not a solution.

Indicator Clues

Question 6mcq

Turmeric stain on a white cloth turns reddish-brown when soap is rubbed on it. What does this show?

A.Soap is acidic in nature.

B.Soap is basic in nature.

C.Turmeric is a metal.

D.The cloth became neutral.

Question 7mcq

What are the usual products when an acid reacts with a base?

A.Sugar and oxygen

B.Carbon and nitrogen

C.Salt and water

D.Only hydrogen gas

Question 8mcq

A student mixes dilute hydrochloric acid with sodium hydroxide solution carefully. Which observation best supports neutralisation?

A.The acid becomes stronger every second.

B.The base changes into sugar.

C.No reaction is possible between acids and bases.

D.The mixture becomes less acidic/basic and forms salt and water.

Question 9mcq

Which pair is correctly classified?

A.Vinegar: acidic; baking soda solution: basic

B.Vinegar: basic; baking soda solution: acidic

C.Distilled water: acidic; soap: neutral

D.Lemon juice: basic; milk of magnesia: acidic

Question 10mcq

A lab record says: “Unknown X turned red litmus blue and did not change blue litmus.” Which label fits X?

A.Acid

B.Base

C.Neutral substance

D.Indicator