NEET

A substance ‘A’ decomposes by a first order reaction starting initially with [A] = 2.00 mol/litre and after 200 sec, [A] = 0.15 mol/litre. For this reaction, what is the value of k ?

1.29 × 10^-2 sec^-1
2.03 × 10^-3 sec^-1
1.80 × 10^-3 sec^-1
1.55 × 10^-2 sec^-1

Solution

In a 1st order reaction, reactant concentration C varies with time t as:

\(\frac{1}{C}\) increases linearly with t
log C decreases linearly with t
C decreases with \(\frac{1}{t}\)
log C decreases with \(\frac{1}{t}\)

Solution

The rate constant of a first order reaction is 6.9 × 10^-3s^-1.How much time will it take to reduce the initial concentration to its 1/8^th value?

100 s
200 s
300 s
400 s

Solution

In a reaction, when the concentration of reactant is increased two times, the increase in rate of reaction was four times.Order of reaction is :

zero
1
2
3

Solution

The rate constant for a first order reaction whose half-life, is 480 seconds is:

2.88 × 10^-3 sec^-1
2.72 × 10^-3 sec^-1
1.44 × 10^-3 sec^-1
1.44 sec^-1

Solution

The order of are action with rate equal to k[A]^3/2[B]^–1/2 is :

1
-\(\frac{1}{2}\)
-\(\frac{1}{2}\)
2

Solution

The concentration of a reactant X decreases from 0.1 M to 0.005 M in 40 min. If the reaction follows first order kinetics,the rate of the reaction when the concentration of X is 0.01 M will be

1.73× 10^-4 M min^-1
3.47 × 10^-4 M min^-1
3.47× 10^-5 M min^-1
7.5 × 10^-4 M min^-1

Solution

In a first order reaction, the concentration of the reactant,decreases from 0.8 M to 0.4 M in 15 minutes. The time taken for the concentration to change from 0.1 M to 0.025 M is

7.5 minutes
15 minutes
30 minutes
60 minutes

Solution

If half-life of a substance is 5 yrs, then the total amount of substance left after 15 years, when initial amount is 64 grams is

16 grams
2 grams
32 grams
8 grams.

Solution

For a chemical reaction which can never be a fraction :

rate constant
order
molecularity
half life

Solution

Molecularity can never be fraction. It is the number of reacting species undergoing simultaneous collision in the elementary or simple reaction. It is a theoretical concept.

UnAttempted

0

Attempted

0

Correct

0

Wrong

0

Complete

Attempted

Correct

UnAttempted

Wrong