MCQ Acids, Bases and Salts

CBSE/NCERT 7th Class MCQ CBSE/NCERT 7th Class MCQ on Science

21-Which of the following statement is true regarding Litmus paper?

a. Litmus paper extracted from lichens.

b. It has a purple colour in distilled water.

c. It turns into red when it is added into acidic solution.

d. It turns into blue when it is added to bases solution.

e. The paper of litmus is generally found in two colour red and blue.

(A) All options are correct

(B) Only a, b, c, d are correct

(C) Only option d and e are correct

(D) All options are incorrect


22- Turmeric is also a

(A) Basic in nature

(B) Natural indicator

(C) Acidic in nature

(D) None of the above


23- China rose petal indicator turns acidic solution to …………….basic solution to ………….

(A) Green and green

(B) Green and Pink

(C) Dark pink and green

(D) No Change


24- Calcium hydroxide is also known as

(A) Salt water

(B) Sugar water

(C) Dilute solution

(D) Lime water


25- The rain containing excess of acids is known as …………..

(A) Changes acid into blue colour

(B) Changes acid into red colour

(C) Simple Rain

(D) Acid rains


26-The rain becomes acidic because of…………….pollutant/s which dissolve in rain drops to form carbonic acid, sulphuric acid and nitric acid.

(A) Carbon dioxide

(B) Sulphur doxide

(C) Nitrogen dioxide

(D) All of the above


27- What is Phenolphthalein?

(A) Base

(B) Indicator

(C) Acid

(D) None of the above


28- What will happen when we mix the acidic and base solution with each other in suitable amount?

(A) acid become basic and basic become acid

(B) Acid remain acid and base remain basic

(C) Both acidic nature of acid and basic nature of base are destroyed

(D) No change takes place both remain the same


29-……………..and……….are formed in neutralisation reaction with evolution of heat.

(A) No formation

(B) Base

(C) Acid

(D) Salt and water


30-Reaction between an acid and a base is known as …………….

(A) Neutralisation

(B) Neutral

(C) Both A and B

(D) None of the above



21-(A), 22-(B), 23-(C), 24-(D), 25-(D), 26-(A), 27-(B), 28-(C), 29-(D), 30-(A)