16. Assertion :Alkyl carbanions like ammonia have pyramidal shape.
Reason: The carbon atom carrying negative charge has an octet of electrons.
17. Assertion: C-H bond in ethyne is shorter than C-H bond in ethane.
Reason: Carbon atom in ethane is sp hybridized while it is spa in ethyne.
18. Assertion: Heat energy is completely transferred into work during the
isothermal expansion of an ideal gas.
Reason: During an isothermal process the change in internal energy of a
gas due to decrease in pressure is multiplied by the change due
to increase due to increase in volume.
19. Assertion: When a catalyst is added to a reaction mixture in equilibrium, 1
the amount of the product increases.
Reason: The forward reaction becomes faster on adding the catalyst.
20. Assertion : One atomic mass unit is defined as one twelfth of the mass of one 1
carbon -12 atom
Reason : Carbon -12 isotope is the most abundant of carbon and has been
Chosen as standard.
Answers
16.If both assertion and reason are correct but reason is not correct explanation for assertion.
17.If assertion is true but reason is false
18.If both Assertion and Reason are true, and reason is the true explanation of Assertion.
19. Assertion is incorrect but Reason is correct.
20.If both assertion and reason are correct but reason is not correct explanation for assertion.
Explanation:
16.
Alkyl carbanions like ammonia have pyramidal shape. Because ammonia and alkyl carbanion have lone pair of electrons on the central atom it makes negative charge on the central atom.
Therefore, both assertion and reason are correct but reason is not correct explanation for assertion.
17.
C-H bond in ethyne is shorter than C-H bond in ethane.Because in ethene the carbon is hybridized.And in ethene is sp hybridized.
Therefore, assertion is true but reason is false.
18.
Assertion and Reason are true, and reason is the true explanation of Assertion.
19.
The amount of reactant and products does not change while adding the catalyst to the reaction it increases only the rate of reaction.
Therefore, Assertion is incorrect but Reason is correct.
20.
An atomic mass unit is defined as approximately 1/12 the mass of an atom of carbon-12.
Therefore, assertion and reason are correct but reason is not correct explanation for assertion.