For questions 1 to 5, two statements are given - one labeled Assertion' (A) and the other
labeled 'Reason' (R). Rend the stntements carefully and select correct answer from the
codes (i, ü, iii, iv) given below:
Both Assertion (A) and Reason (R) are correct statements, and Reason (R) is the correct
explanation of the Assertion (A).
ii. Both Assertion (A) and Reason (R) are correct statements, but Reason (R) is not the
correct explanation of the Assertion (A).
Assertion (A) is correct but Reason (R) is incorrect.
iv. Assertion (A) is incorrect, but Reason (R) is correct.
1. A: The empirical mass of ethene (H2C=CH2) is half of its molecular mass
R: The empirical formula represents the simplest whole number ratio of various atoms
present in a compound.
2. A: It is impossible to determine the exact position and exact momentum of an electron
simultaneously
R: The path of an electron in an atom is clearly defined
3. A: First ionization energy of nitrogen is lower than that of oxygen
R: Across a period effective nuclear charge increases
4. A: BF; molecule is planar while NF; molecule is pyramidal
R: Batom is smaller than N atom
5. A: Three states of matter are result of balance between intermolecular forces and thermal
energy of the molecules
R: Intermolecular forces tend to keep the molecule together but thermal energy tends to keep
them apart
Answers
Answer:
ln these questions (Q. No i - iv, a statement of assertion followed by a statement of
reason is given. Choose the correct answer out of the following choices.
a) Assertion and reason both are corred statements and reason is correct explanation
for assertion
b) Assertion and reason both are correct statements but reason is not correct
explanation for assertion.
Assertion is correct statement but reason is wrong statement,
d) Assertion is wrong statement but reason is correct statement.
1
0 Assertion: 4p orbital will be occupied by an electron before 5s orbital
Reason: (n+1) value is higher for 4p than 5s
(a) Assertion: 3s orbital can be described by n=3,1 = 0 and m=0
Reason: No two electrons can have same 4 quantum numbers
(ii) Assertion: If 3d has 5 electrons all the 5 will have either + oras s value
Reason: Electrons in singly occupied degenerate orbitals will have minimum repulsion
when they have parallel spins
(iv) Assertion: Electrons will enter 4s subshell after the 3p subshell gets filled with 3
electrons
Reason: Lower energy orbitals are filled first