All In One ISC Chemistry Class 12>Chapter 18 - Sample Question Paper 3>SAMPLE QUESTION PAPER 3>Q 16

MEDIUM

12th ICSE

IMPORTANT

Earn 100

Describe how does the enthalpy of reaction remains unchanged when a catalyst is used in the reaction.

Important Questions on Sample Question Paper 3

MEDIUM

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 18 - Sample Question Paper 3>SAMPLE QUESTION PAPER 3>Q 16 or

All energetically effective collisions do not result in a chemical change. Explain with the help of an example.

HARD

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 18 - Sample Question Paper 3>SAMPLE QUESTION PAPER 3>Q 16 or

A specific reaction is

50 %

complete in

20

minutes at

300 K

and the same reaction is again

50 %

completes in

5

minutes at

350 K

. Calculate the activation energy if it is a first order reaction.

MEDIUM

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 18 - Sample Question Paper 3>SAMPLE QUESTION PAPER 3>Q 17

Give a reason for the following:

Mn (II)

ion show maximum paramagnetic character amongst the bivalent ion of first transition series.

EASY

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 18 - Sample Question Paper 3>SAMPLE QUESTION PAPER 3>Q 17

Give reason for the following observation: In series $Sc$ to $Zn$ , enthalpy of atomization of $Zn$ is the lowest.

EASY

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 18 - Sample Question Paper 3>SAMPLE QUESTION PAPER 3>Q 17

Give the reason for the following observation:

Sc

(atomic number

21

) salts are white.

HARD

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 18 - Sample Question Paper 3>SAMPLE QUESTION PAPER 3>Q 17

Describe the reactions involved in the preparation of

K_{2} {Cr}_{2} O_{7}

from chromite ore.

EASY

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 18 - Sample Question Paper 3>SAMPLE QUESTION PAPER 3>Q 17 or

Give a reason for the following: Size of trivalent lanthanoid cations decreases with increase in the atomic number.

EASY

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 18 - Sample Question Paper 3>SAMPLE QUESTION PAPER 3>Q 17

Give reason for the following: Ionisation enthalpies of

Ce, \Pr

and

Nd

are higher than

Th, Pa

and

U

.