Chemistry MCQ Questions with Answer
Q21. Which one among the following equations is correctly balanced?
(a) NaOH + Al + H2O → 2H2 + NaAlO2
(b) 2NaOH + 2Al + 2H2O → 3H2 + 2NaAlO2
(c) 2NaOH + 2Al + 3H2O → 4H2 + 2NaAlO2
(d) 2NaOH + 2Al + H2O → H2 + 2NaAlO2
Q22. What are Rubies and Sapphires chemically known as?
(a) Silicon dioxide
(b) Aluminium oxide
(c) Lead tetroxide
(d) Boron nitride
Q23. Benzene is ______ in ethyl alcohol.
Q24. Helium gas is filled in the balloon instead of Hydrogen because its–
(a) Lighter than Hydrogen
(b) More abundant than Hydrogen
(d) More stable
Q25. The rusting of iron nail
(a) Decreases its weight
(b) Increases its weight
(c) Does not affect weight but iron is oxidized
(d) Does not affect weight but iron is reduced
Q26. The metal constituent of chlorophyll is
Q27. Match List-I (Industrial process) with List-II (Industry with which associated) and select the correct answer using the codes given below the lists:
|List-I (Industrial process)||List-II (Industry with which associated)|
|A. Cracking||1. Rubber|
|B. Smelting||2. Petroleum|
|C. Hydrogenation||3. Copper|
|D. Vulcanization||4. Edible fats|
(a) A-3; B-2; C-1; D-4
(b) A-2; B-3; C-4; D-1
(c) A-2; B-3; C-1; D-4
(d) A-3; B-2; C-4; D-1
Q28. Why Helium gas used in balloons?
(a) Its atomic number is two
(b) Its Lighter than air
(c) It’s one of the constituents of water
(d) It’s a noble gas
Q29. What is used to prevent the freezing of fuel in space crafts?
Q30. The tracking of people by trained dogs is based on the recognition of which of the following compounds in the sweat from feet?
(a) Carboxylic acids
(b) Uric acid