1) LDP is low density polyethylene and HDP is high density polyethylene. 2) LDP is density a branched polymer with low density due to chains are loosely held and HDP is a linear polymer with density due to close packing. 3) HDP is much stiffer than LDP and has high tensile strength and hardness. LDP is mainly used in preparation of pipes for agriculture, irrigation and domestic water line connections. HDP is used in manufacture of toys and other household articles like bucket, bottles, etc.

Fe + 2 → Fe 3 + + e - ( E ° = 0 . 77 V ) ; Ag + + e - → Ag ( E ° = 0 . 80 V ) . Calculate the emf of the following cell reaction at 25 ° C .

Given : E ° ( Fe 2 + / Fe 3 + ) = 0 . 77 V E ° ( Ag + / Ag ) = 0 . 80 V Solution: Standard EMF of the cell = E ° cathode - E ° anode = + 0 . 80 - 0 . 77 V = + 0 . 03 V Hence, the standard reduction potential of the galvanic cell is + 0 . 03 V .

Why is use of aspartame limited to cold foods and drinks?

Aspartame is an artificial sweetening agent which is 100 times as sweet as sucrose. The use of aspartame limited to cold foods and drinks because aspartame is unstable at cooking temperature. Note : The chemical formula of aspartame can be given as : C 14 H 18 N 2 O 5 .

E M B I B E

All In One ISC Chemistry Class 12>Chapter 20 - Sample Question Paper 5>SAMPLE QUESTION PAPER 5>Q 3

HARD

12th ICSE

IMPORTANT

Earn 100

Explain LDP and HDP.

Important Questions on Sample Question Paper 5

MEDIUM

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 20 - Sample Question Paper 5>SAMPLE QUESTION PAPER 5>Q 4

Out of the four bases in DNA and RNA, name those which are common to both DNA and RNA.

MEDIUM

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 20 - Sample Question Paper 5>SAMPLE QUESTION PAPER 5>Q 5

Out of physisorption or chemisorption, which has a higher enthalpy of adsorption.

EASY

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 20 - Sample Question Paper 5>SAMPLE QUESTION PAPER 5>Q 6

The mole fraction of toluene in a solution of benzene is

0.50

. Calculate the weight percent of toluene in solution.

MEDIUM

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 20 - Sample Question Paper 5>SAMPLE QUESTION PAPER 5>Q 6

A solution is prepared by

1.25 g

of oil of wintergreen (methyl salicylate) in

99 g

of benzene has a boiling point of

80.31 ° C

and

K_{b}

for benzene is

2.53 K Kg {mol}^{- 1}

. Find the molar mass of the solute. Boiling point of benzene is

80 ° C

.

HARD

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 20 - Sample Question Paper 5>SAMPLE QUESTION PAPER 5>Q 7

Xenon crystallises in the face-centred cubic lattice and the edge of the unit cell is

620 pm

. What is the nearest neighbour distance and radius of the xenon atom?

EASY

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 20 - Sample Question Paper 5>SAMPLE QUESTION PAPER 5>Q 8

${Fe}^{+ 2} \to {Fe}^{3 +} + e^{-} (E ° = 0.77 V); {Ag}^{+} + e^{-} \to Ag (E ° = 0.80 V)$ . Calculate the emf of the following cell reaction at $25 ° C$ .