CBSE Class 11 Chemistry Some Basic Concepts of Chemistry MCQs

MCQ - Choose Appropriate Alternative

1. The process in which a solid directly changes to vapours without melting is called __________. (Evaporation, Condensation, Sublimation)

2. The oxidation number of P in PO3^-4 is __________. (3+, 5+, 3-)

3. The pH of 0.001 M HCl is __________. (2, 4, 3)

4. K ( rate constant) is dependent on __________. (temperature, concentration, volume)

5. The universal indicator in water shows the colour __________. (red, green, blue)

6. The pH of blood is __________. (7.3, 8.4, 5.6)

7. The oxidation potential of hydrogen electrode is __________. (0.0 volt, +0.76volt, -0.36volt)

8. __________ quantum number describes the shape of a molecule. (Pricipal, Azimuthal, Spin)

9. An orbital can have the maximum number of two electrons but with opposite spin, it is called __________. (Pauli’s Exclusion Principle, Hund’s Rule, Aufbau Principle)

10. When a-particle is emitted from the nucleus of radioactive element, the mass number of the atom __________. (Increases, Decreases, Does not change)

11. Dissociation of KClO₃ is a __________ process. (Reversible, Irreversible)

12. The e/m ratio of cathode rays is the __________ when Hydrogen is taken in the discharge tube. (Lowest, Highest)

13. The negative ion tends to expand with the __________ of negative change on it. (Decreases, Increases)

14. Ionic compounds have __________ melting points. (Low, High)

15. The allotropic forms of an element are called __________. (Polymorphs, Isomorphs)

16. Absolute Zero is equal to __________. (273.16°C, -273.16°C)

17. The compounds having hydrogen bond generally have __________ boiling points. (High, Low)

18. Surface tension __________ with the rise of temperature. (Increases, Decreases)

19. Mercury forms __________ meniscus in a glass tube. (concave, convex)

20. The reactions with the high value of energy of activation are __________. (slow, fast)

21. 2.000 has/have __________ significant figure(s). (1, 4)

22. E + PV is called __________. (Entropy, Enthalpy)

23. The shorter the bond length in a molecule, the __________ will be bond energy. (Lesser, Greater)

24. Positive rays are produced from __________. (Anode, Cathode, Ionization of gas in a discharge tube)

25. __________ of the following contains the fewer number of molecules. (1 gm of hydrogen, 4 gm of oxygen, 2 gm of nitrogen)

26. the true statement about the average speed of the molecules of hydrogen, oxygen and nitrogen confined in a container is __________. (Hydrogen is quicker, Oxygen is quicker, The molecules of all the gases have the same average speed)

27. The correct statement about the glass is __________. (It is crystalline solid, Its atoms are arranged in an orderly fashion, It is a super cooled liquid)

28. When a substance that has absorbed energy emits it in the form of radiation the spectrum obtained is__________.(Continuous Spectrum, Line Spectrum, Emission Spectrum)

29. __________ of the overlap forms strong bond.(s-s, p-s, p-p)

30. __________ compound has a greater angle between a covalent bond.(H₂O, NH₃, CO₂)

31. When sodium chloride is mixed in water then __________.(pH is changed, NaOH and HCl are formed, Sodium and chloride ions become hydrated)

32. The boiling point of a liquid __________ with an increase in pressure.(Decreases, Increases, remains constant)

33. An Azimuthal Quantum Number describes the __________.(size of an atom, shape of an orbital, spin of orbital)

34. The rate of the backward reaction is directly proportional to the product of the molar concentration of __________.(Reactants, Products, None of them)

II. Fill in the Blank

1. The property of a crystal, which is different in different directions, is called __________.

2. 0.00051 contains __________ significant figures.

3. The oxidation number of oxygen in OF₂ is __________.

4. The volume of 1 gm of hydrogen gas at S.T.P is __________.

5. The oxidation number Mn in KMnO₄ is __________.

6. The product of ionic concentration in a saturated solution is called __________.

7. 16 gm of oxygen at S.T.P occupies a volume of __________ dm3.

8. The shape of the orbital for which l = 0 is __________.

9. The radius of Cl^-1 is __________ than the radius of Cl0.

10. sp² hybridization is also known as __________.

11. The value of 1 Debye is __________.

12. The reactions catalyzed by sunlight are called __________.

13. The blue colour of CuSO₄ is due to the presence of __________.

14. The force of attraction between the liquid molecules and the surface of container is called __________.

15. The heat of neutralization of a strong acid and a strong base is __________.

16. C º C triple bond is __________. C = C double bond length.

17. The ions having the same electronic configuration are called iso electronic.

18. On heating, if a solid changes directly into vapours without changing into the liquid state, the phenomenon is called __________.

19. Each orbital in an atom can be completely described by __________.

20. In a molecule of alkene, __________ restricts the rotation of the group of atoms at either end of the molecule.

21. Density, refractive index and vapour pressure are __________ properties.

22. The addition of HCl to H₂ solution __________ the ionization of H₂S.

23. The reaction of cation or anion (or both) with water so as to change its __________ is known as Hydrolysis.

24. A reaction with higher activation energy will start at __________ temperature.

25. 6.02 x 10²³ has __________ significant figures.

26. The internal resistance in the flow of liquid is called __________.