12th Chemistry MCQ Questions and Answers in English-2020

12th Chemistry MCQ Questions and Answers in English-2020

1 . The number of particles in a simple cubic per unit cell is :

One
two
three
four

Ans. One

2. The number of particles in a face-centered cubic (fcc) per unit cell is

one
two
three
Four

Ans. Four

3. The number of particles in a body-centered cubic (bcc) per unit cell IS :

one
Two
Three
Four

Ans. Two

4. Graphite is an example of

·         Ionic Solid

·         Molecular Solid

·         Covalent Solid

·         Metallic Solid

Ans. Covalent Solid

5. Possible Co-ordination number of Cation of tetrahedral structural Arrangement is:

·         1

·         2

·         3

·         4

Ans. 4

6. The molecularity of a reaction cannot be :

·         Zero

·         One

·         Two

·         Three

Ans. Zero

7. Cuprite is an ore of

·         Zn

·         Cu

·         Ag

·         Fe

Ans. Cu

8. Calamine is an ore of :

·         Cu

·         Fe

·         Al

·         Zn

Ans. Zn

9. Bauxite is an ore of :

·         Al

·         Fe

·         Cu

·         Zn

Ans. Al

10. Sulphide ores are generally concentrated by :

·         Gravity separation method

·         Magnetic separation method

·         Froth floatation process

·         None of these

Ans. Froth floatation process

11. Haematite is an ore of :

·         Al

·         Fe

·         Cu

·         Zn

Ans. Fe

12. Unit Of rate constant for Second-order reaction, K is :

·         s⁻¹

·         mol⁻¹ L s⁻¹

·         mol⁻² L² s⁻¹

·         mol L⁻¹ s⁻¹

Ans. mol⁻¹ L s⁻¹

13. Unit Of rate constant for First-order reaction, K is :

·         s⁻¹

·         mol⁻¹ L s⁻¹

·         mol⁻² L² s⁻¹

·         mol L⁻¹ s⁻¹

Ans. s⁻¹

14. Unit Of rate constant for third-order reaction, K is :

·         s⁻¹

·         mol⁻¹ L s⁻¹

·         mol⁻² L² s⁻¹

·         mol L⁻¹ s⁻¹

Ans. mol⁻² L² s⁻¹

15. When nitroethane is treated with Li Al H4 the product formed is :

·         Methyl amine

·         Ethyl amine

·         Ethane

·         Acetamide

Ans. Ethyl amine

16. Aldehyde and ketone can be distinguished by :

·         Tollen’s reagent

·         LiAIH4

·         HCN

·         None of these

Ans. Tollen’s reagent

17. Among the halogen acids the one which is weakest is :

·         HBr

·         HI

·         HF

·         HCI

Ans. HF

18. Which of the following is artificial sweetening agent :

·         Aspartame

·         Seconal

·         Aspirin

·         Sodium benzoate

Ans. Aspartame

19. Acid chloride is reduced to aldehyde by :

·         wurtz reaction

·         Fittig reaciton

·         Rosenmund reduction

·         None of these

Ans. Rosenmund reduction

20. Tollen’s reagent is:

·         Mixture of CuSO4 and NaOH

·         A solution of copper sulphate, sodium citrate and sodium carbonate

·         Ammonical silver nitrate solution

·         None of these

Ans. A solution of copper sulphate, sodium citrate and sodium carbonate

21. Phenol is less acidic than:

·         Ehanol

·         Methanol

·         p-Nitrophenol

·         p- methylphenol

Ans. p-Nitrophenol

22. The hybridization of Xe F2 Is :

·         sp³d²

·         sp³d

·         sp³

·         sp³d³

Ans. sp³d

23. The hybridisation of Xe F4 Is :

·         sp³d²

·         s³d
sp³
sp³d³

Ans. sp³d²

24. Which one of the following is not a protein:

·         Nail

·         DNA

·         Hair

·         Wool

Ans. DNA

25. Enzymes are:

·         Carbohydrates

·         Vitamins

·         Proteins

·         None of these

Ans. Proteins

26. Vitamin A is Called

·         Retinol

·         Ascorbic acid

·         calciferol

·         Tocoferol

Ans. Retinol

27. which of the Following is not found in RNA

·         Uracil

·         Adenine

·         Ammonium Acetate

·         Guanine

Ans. Ammonium Acetate

28. PVC is a

·         Addition polymer

·         Condensation polymer

·         copolymer

·         None of these

Ans. Addition polymer

29. Phenol is used as :

·         Antiseptic

·         Disinfectants

·         Both a & b

·         None

Ans. Both a & b

30. Antipyretics is a :

·         Quinone

·         Paracetamol

·         Luminal

·         None

Ans. Paracetamol