chemistry : class11 Percentage Ionic Character : Polar character of covalent bond : Chemical Bonding and Molecular Structure MCQ Questions and Answers
Practice important
Percentage Ionic Character
MCQ questions and answers.
Page 1
of
1
|
10
MCQ Questions
1. Percentage ionic character of a covalent bond is calculated using the ratio of observed dipole moment to theoretical dipole moment. Which expression is correct?
A.
Percentage ionic character = (theoretical dipole moment / observed dipole moment) × 100
B.
Percentage ionic character = (observed dipole moment / theoretical dipole moment) × 100
C.
Percentage ionic character = observed dipole moment + theoretical dipole moment
D.
Percentage ionic character = observed dipole moment − theoretical dipole moment
Correct Answer:
Percentage ionic character = (observed dipole moment / theoretical dipole moment) × 100
Explanation:
The percentage ionic character is obtained by comparing the observed dipole moment with the dipole moment expected for complete charge separation, using (observed dipole moment / theoretical dipole moment) × 100.
2. A covalent molecule has an observed dipole moment of 1.0 D and a theoretical dipole moment of 2.0 D. What is its percentage ionic character?
A.
25%
B.
50%
C.
75%
D.
100%
Correct Answer:
50%
Explanation:
Percentage ionic character = (1.0 D / 2.0 D) × 100 = 50%.
3. If the observed dipole moment of a bond is equal to its theoretical dipole moment for complete charge separation, what is its percentage ionic character?
A.
0%
B.
25%
C.
50%
D.
100%
Correct Answer:
100%
Explanation:
When the observed and theoretical dipole moments are equal, their ratio is 1. Therefore, the percentage ionic character is 1 × 100 = 100%.
4. A bond has an observed dipole moment of 0.8 D and a theoretical dipole moment of 4.0 D. Its percentage ionic character is:
A.
10%
B.
20%
C.
40%
D.
80%
Correct Answer:
20%
Explanation:
Percentage ionic character = (0.8 D / 4.0 D) × 100 = 20%.
5. Which change generally increases the percentage ionic character of a covalent bond according to the electronegativity difference approach?
A.
Decrease in electronegativity difference
B.
Increase in electronegativity difference
C.
Decrease in bond length only
D.
Decrease in molecular mass only
Correct Answer:
Increase in electronegativity difference
Explanation:
A larger difference in electronegativity between the bonded atoms causes greater separation of charge, increasing the percentage ionic character.
6. According to the approximate Pauling relation, percentage ionic character depends mainly on the:
A.
Sum of atomic masses
B.
Difference in electronegativities of bonded atoms
C.
Number of neutrons in the atoms
D.
Boiling point of the compound
Correct Answer:
Difference in electronegativities of bonded atoms
Explanation:
The Pauling relation connects percentage ionic character with the electronegativity difference between the two bonded atoms.
7. A bond has 30% ionic character. If its theoretical dipole moment is 5.0 D, what is its observed dipole moment?
A.
0.5 D
B.
1.5 D
C.
3.0 D
D.
5.0 D
Correct Answer:
1.5 D
Explanation:
Using percentage ionic character = (observed dipole moment / theoretical dipole moment) × 100, observed dipole moment = 30/100 × 5.0 D = 1.5 D.
8. A bond has an observed dipole moment of 1.2 D and a theoretical dipole moment of 1.5 D. What is its percentage ionic character?
A.
20%
B.
40%
C.
80%
D.
125%
Correct Answer:
80%
Explanation:
Percentage ionic character = (1.2 D / 1.5 D) × 100 = 80%.
9. A covalent bond with a smaller percentage ionic character has:
A.
A greater contribution from complete charge separation
B.
A smaller contribution from ionic character
C.
Exactly 100% ionic character
D.
No covalent character at all
Correct Answer:
A smaller contribution from ionic character
Explanation:
Percentage ionic character indicates the extent of ionic contribution to a covalent bond. A smaller percentage means a smaller ionic contribution.
10. If the observed dipole moment is one-fourth of the theoretical dipole moment, the percentage ionic character is:
A.
4%
B.
25%
C.
50%
D.
75%
Correct Answer:
25%
Explanation:
Percentage ionic character = (1/4) × 100 = 25%.
Short Questions and Answers
Practice short questions and answers related to
Percentage Ionic Character
.
Short questions are currently unavailable for this page.