For the reaction, N 2 + 3 H 2 → 2 NH 3 , the rate of change of concentration for hydrogen is 0 . 3 × 10 - 4 Ms - 1 . What will be the rate of change of concentration of ammonia?

Given: ∆ [ H 2 ] ∆ t = 0 . 3 × 10 - 4 M s - 1 . Solution: For the given reaction, N 2 + 3 H 2 → 2 NH 3 , Rate of reaction ( r ) = - ∆ [ N 2 ] ∆ t = - 1 3 ∆ [ H 2 ] ∆ t = + 1 2 ∆ [ NH 3 ] ∆ t . The rate of change in concentration of NH 3 : ( r ) = - 1 3 ∆ [ H 2 ] ∆ t = + 1 2 ∆ NH 3 ∆ t ∆ NH 3 ∆ t = 2 3 × ∆ [ N 2 ] ∆ t = 2 3 × 0 . 3 × 10 - 4 = 0 . 2 × 10 - 4 M s - 1

For a reaction between A and B, the initial rate of reaction is measured for various initial concentrations of A and B . The data provided is : A B Initial rate mol L - 1 s - 1 0 . 020 0 . 010 2 . 40 × 10 - 4 0 . 020 0 . 030 2 . 16 × 10 - 3 0 . 040 0 . 030 4 . 32 × 10 - 3 Calculate the overall order of the reaction.

Rate law can be given as : Rate, r = k A x B y , where k is rate constant. For the given reactant concentrations, rate equations can be given as : 2 . 40 × 10 - 4 = k 0 . 020 x 0 . 010 y 2 . 16 × 10 - 3 = k 0 . 020 x 0 . 030 y 4 . 32 × 10 - 3 = k 0 . 040 x 0 . 030 y Dividing the first two rate equations : 2 . 40 × 10 - 4 2 . 16 × 10 - 3 = k 0 . 020 x 0 . 010 y k 0 . 020 x 0 . 030 y 3 y = 9 y = 2 Dividing the second and third rate equations : 4 . 32 × 10 - 4 2 . 16 × 10 - 3 = k 0 . 040 x 0 . 030 y k 0 . 020 x 0 . 030 y 2 x = 2 x = 1 The over order of reaction = 2 + 1 = 3 .

A first order reaction has a rate constant 1 . 15 × 10 - 3 s - 1 . How long will 5 g of this reactant take to reduce to 3 g ?

Given : k = 1 . 15 × 10 - 3 s - 1 Integrated rate equation for first order reactions : t = 2 . 303 k log A ∘ A t . So, t = 2 . 303 1 . 15 × 10 - 3 s - 1 log 5 3 t = 2 × 10 3 × log 5 - log 3 t = 2 × 10 3 × 0 . 698 - 0 . 477 t = 2 × 10 3 × 0 . 221 t = 442 s

E M B I B E

All In One ISC Chemistry Class 12>Chapter 19 - Sample Question Paper 4>SAMPLE QUESTION PAPER 4

SAMPLE QUESTION PAPER 4

Author:Saleha Pervez & Vandana

Saleha Pervez Chemistry Solutions for Exercise - SAMPLE QUESTION PAPER 4

Simple step-by-step solutions to SAMPLE QUESTION PAPER 4 questions of Sample Question Paper 4 from All In One ISC Chemistry Class 12. Also get 3D topic explainers, cheat sheets, and unlimited doubts solving on EMBIBE.

Questions from SAMPLE QUESTION PAPER 4 with Hints & Solutions

HARD

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 19 - Sample Question Paper 4>SAMPLE QUESTION PAPER 4>Q 7

Calculate the emf of the cell in which the given reaction takes place: $Ni (s) + 2 {Ag}^{+} (0.002 M) \to {Ni}^{2 +} (0.160 M) + 2 Ag$ . Given that $E °_{cell} = 1.05 V$ .

HARD

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 19 - Sample Question Paper 4>SAMPLE QUESTION PAPER 4>Q 7

Can you store copper sulphate solution in a zinc vessel?

HARD

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 19 - Sample Question Paper 4>SAMPLE QUESTION PAPER 4>Q 16

Consider the reaction, $A \to P$ . The change in the concentration of A with time is shown in the following plot.

Question Image

Predict the order of reaction.

HARD

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 19 - Sample Question Paper 4>SAMPLE QUESTION PAPER 4>Q 16

For the reaction, $N_{2} + 3 H_{2} \to 2 {NH}_{3}$ , the rate of change of concentration for hydrogen is $0.3 \times 10^{- 4} {Ms}^{- 1}$ . What will be the rate of change of concentration of ammonia?

HARD

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 19 - Sample Question Paper 4>SAMPLE QUESTION PAPER 4>Q 16

For a reaction between A and B, the initial rate of reaction is measured for various initial concentrations of $A$ and $B$ . The data provided is :

$[A]$	$[B]$	Initial rate $(mol L^{- 1} s^{- 1})$
$0.020$	$0.010$	$2.40 \times 10^{- 4}$
$0.020$	$0.030$	$2.16 \times 10^{- 3}$
$0.040$	$0.030$	$4.32 \times 10^{- 3}$