Assertion (A) & Reason (B) MCQ

MCQ 11 Mark

Assertion (A): The standard unit for expressing the mass of atoms is a.m.u.
Reason (R): a.m.u. stands for mass of 1 atom of carbon.

A
Both A and R are true and R is the correct explanation of A.
B
Both A and R are true but R is not the correct explanation of A.
✓
A is true but R is false.
D
A is false but R is true.

Answer

Correct option: C.

A is true but R is false.

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MCQ 21 Mark

Assertion (A): In case of isoelectronic ions the ionic size increases with the increase in atomic number.
Reason (R): The greater the attraction of nucleus, greater is the ionic radius.

A
Both A and R are true and R is the correct explanation of A.
B
Both A and R are true but R is not the correct explanation of A.
C
A is true but R is false.
✓
A is false but R is true.

Answer

Correct option: D.

A is false but R is true.

(d) Both A and R are false.
Explanation: In case of isoelectronic ions, i.e., ions, having the same number of electrons and different nuclear charge, the size decreases with increase in atomic number.

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MCQ 31 Mark

Assertion (A): Fluoride has the lowest and iodide has the highest boiling point.
Reason (R): Boiling points of haloalkanes increases with increasing atomic mass.

✓
Both A and R are true and R is the correct explanation of A.
B
Both A and R are true but R is not the correct explanation of A.
C
A is true but R is false.
D
A is false but R is true.

Answer

Correct option: A.

Both A and R are true and R is the correct explanation of A.

(a) Both A and R are true and R is the correct explanation of A .
Explanation: For a given halogen the boiling point rises with increasing atomic mass of the halogen, so that fluoride has the lowest boiling point and iodide has the highest boiling point.

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MCQ 41 Mark

Assertion (A): Moving phase is liquid and stationary phase is solid in paper chromatography.
Reason (R): Paper chromatography is used for analysis of polar organic compounds.

A
Both A and R are true and R is the correct explanation of A.
B
Both A and R are true but R is not the correct explanation of A.
C
A is true but R is false.
✓
A is false but R is true.

Answer

Correct option: D.

A is false but R is true.

(d) $A$ is false but $R$ is true.
Explanation: Paper chromatography is a liquid-liquid partition chromatography in which the water adsorbed or chemically bond to cellulose of paper acts as the stationary phase while the mobile phase is another liquid which is usually a mixture of two or three solvents in which water is one of the components.

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Chemistry Assertion (A) & Reason (B) MCQ

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