Acids, Bases and Salts Class 10 MCQ with Answers Set-3
21. At what temperature is gypsum heated to form Plaster of Paris?
A. 90°C
B. 100°C
C. 110°C
D. 120°C
Answer –B. 100°C
Explanation-
22. When a solution of an acid contains larger amount of acid, it is said to be-
A. Dilute
B. Concentrated
C. Mono basic
D. poly-basic
Answer –B. Concentrated
Explanation-
23. How many water molecules does hydrated calcium sulphate contain?
A. 5
B. 10
C. 7
D. 2
Answer –D. 2
Explanation-
24. Bleaching powder is soluble in cold water, giving a milky solution due to
A. Available chlorine
B. Lime present in it
C. Calcium carbonate formation
D. The absorption of carbon dioxide from atmosphere
Answer –B. Lime present in it
Explanation-
25. Metals like sodium, potassium and calcium react with an acid to liberate-
A. CO2
B. NH3
C. O2
D. H2
Answer –D. H2
Explanation-
26. A blue litmus paper was first dipped in dilute HCl and then in dilute NaOH It was observed that the color of the litmus paper:
A. Changed to red
B. Changed first to red and then to blue
C. Changed blue to colorless
D. Remains blue in both the solutions
Answer –B. Changed first to red and then to blue
Explanation-Blue litmus turns red in an acid and turns blue in a basic solution. Thus, blue litmus first turns red before turning blue.
27. In which pH range does our body work to survive in the atmosphere?
A. 5.5 to 8.5
B. 7.0 to 7.8
C. 2.3 to 7.0
D. 7.5 to 12.5
Answer –B. 7.0 to 7.8
Explanation-
28. Which of the following is a weak acid?
A. sulphuric acid
B. hydrochloric acid
C. acetic acid
D. nitric acid
Answer –C. acetic acid
Explanation-
29. H3PO4 is the example of-
A. hydracids
B. organic acid
C. oxyacid
D. salt
Answer –C. oxyacid
Explanation-
30. Which substance is used to purify water
A. Ammonium chloride
B. copper sulphate
C. chlorine
D. none of these
Answer –C. chlorine
Explanation-
