Subject

Chemistry

Class

NEET Class 12

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 Multiple Choice QuestionsMultiple Choice Questions

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11.

Hydrofluoric acid is a weak acid. At 25°C, the molar conductivity of 0.002 M HF is 176.2 Ω-1cm2 mol-1. If its °m = 405.2 Ω-1 cm2 mol-1. Equilibrium constant at the given concentration is

  • 6.7 × 10-4 M

  • 3.2 × 10-4 M

  • 6.7 × 10-5 M

  • 3.2 × 10-5 M


A.

6.7 × 10-4 M

α = cm = 176.2 Ω-1 cm2 mol-1405.2 Ω-1 cm2 mol-1 = 0.435K = H+F-1HF = 21 - α = 0.002 M0.43521 - 0.435   = 6.7×10-4 M = 6.70 × 10-4 M


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12.

Incorrect statement about Ge is

  • GeO2 is weakly acidic

  • Ge(OH)2 is amphoteric

  • GeCl2 is more stable than GeCl4

  • Ge-Ge bond energy is lesser than that of Si - Si.


13.

In an isobaric process, when temperature changes from T1 to T2 ,S is equal to

  • 2.303 Cp log (T2/T1)

  • 2.303 Cp ln (T2/T1)

  • Cp ln (T1/T2)

  • Cv ln (T2/T1)


14.

Assertion : Heat of neutralisation of nitric acid with NaOH is same to that of HCI and NaOH.

Reason : In both cases strong acid and strong bases are neutralised.

H+ + OHH2O

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false.


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15.

Assertion : A reaction which is spontaneous and accompanied by decrease of randomness must be exothermic.

Reason : All exothermic reactions are accompanied by decrease of randomness.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false


16.

Assertion: The S-S-S bond angle in S8 molecule is 105°.

Reason : S8 has a V-shape.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false


17.

Assertion : Sodium formate has both the C-O bonds have same value 1.27Å.

Reason : Equal bond length is due to the phenomenon of resonance.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false


18.

Assertion : Ice  water, if pressure is applied water will evaporate.

Reason : Increases of pressure pushes the equilibrium towards the side in which number of gaseous molecule increases.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false


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19.

Assertion : In an acid-base titration involving strong base and a weak acid, methyl orange can be used as an indicator.

Reason : Methyl orange changes its colour in pH range of 7 to 9.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false


20.

Which of the following shows bond in silicone?

  • Si-C-Si-C-Si

  • Si-Si-Si-Si

  • -Si-O-Si-O-Si-

  • Si-C-Si-O-Si


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