Chemistry by Naveen sir

31/01/2025

Important theory Questions from Haloalkanes and Haloarenes

31/01/2025

22/07/2023

CHEMICAL KINETICS
(For: 12th, NEET, JEE Mains)
(By: Naveen sir(8860432726)

1) What will be the fraction of molecules having energy equal to or greater than activation energy, Ea?
(a) K
(b) A
(c) Ae-Ea/Rt
(d) e-Ea/Rt

2) What type of reaction is this?
CH3COOCH3 + H20 → CH3COOH + CH3OH
(a) Second order
(b) Unimolecular
(c) Pseudo-unimolecular
(d) Third order

3) Which among the following is a false statement?
(a) Rate of zero order reaction is independent of initial concentration of reactant.
(b) Half life of a third order reaction is inversely proportional to square of initial concentration of the reactant.
(c) Molecularity of a reaction may be zero or fraction.
(d) For a first order reaction, t1/2=0.693K

4). Which of the following statements about the catalyst is true?
(a) A catalyst accelerates the rate of reaction by bringing down the activation energy.
(b) A catalyst does not participate in reaction mechanism.
(c) A catalyst makes the reaction feasible by making ∆G more negative.
(d) A catalyst makes equilibrium constant
more favourable for forward reaction.

5) For the reaction N2 + 3H2 → 2NH3 if Δ[NH3]Δt = 2 × 10-4 mol L-1s-1, the value of −Δ[H2]Δt would be
(a) 1 × 10-4 mol L-1s-1
(b) 3 × 10-4 mol L-1s-1
(c) 4 × 10-4 mol L-1s-1
(d) 6 × 10-4 mol L-1s-1

6) The rate of a certain hypothetical reaction
A + B + C → products
is given by r = −d[A]/dt
=K[A]1/2[B]1/3[C]1/4. The order of the reaction is
(a) 13/11
(b) 13/14
(c) 12/13
(d) 13/12

7) In the formation of S02 by contact process;
2SO2 + O2 → 2SO3, the rate of reaction was measured as −d[O2]/dt = 2.5 × 10-4 mol L-1s-1. at
The rate of formation of of S03 will be
(a) -5.0 × 10-4 mol L-1s-1
(b) -1.25 × 10-4 mol L-1s-1
(c) 3.75 × 10-4 mol L-1s-1
(d) 5.00 × 10-4 mol L-1s-1

8) For a chemical reaction A→B, it is found that the rate of reaction doubles when the concentration of A is increased four times. The order of reaction is
(a) Two
(b) One
(c) Half
(d) Zero

9) The half life of the first order reaction having rate constant K = 1.7 x 10-5s-1 is
(a) 12.1 h
(b) 9.7 h
(c) 11.3 h
(d) 1.8 h
10) For a chemical reaction A → B, it is found that the rate of the reaction quardruples when the concentration of A is doubled. The rate expression for the reaction is, rate = k [A]n where the value of n is
(a) 1
(b) 2
(c) 0
(d) 3

11) The reaction of high molecularity are rare because
(a) Many body collisions have a low probability.
(b) Many body collisions are not favoured energetically.
(c) Activation energy of many body collisions is very large
(d) Very high concentration is required for such reaction

12) On increasing the temperature of the reacting system by 10° the rate of reaction almost becomes double. The most appropriate reason for this is that
(a) Activation energy decreases by increases of temperature
(b) The fraction of molecules having threshold energy increases
(c) Collision frequency increases
(d) The value of threshold energy decreases.

13) The half-life period of any first order reaction
(a) is half the specific rate constant
(b) is always the same irrespective of the reaction
(c) is independent of initial concentration
(d) in directly proportional to initial concentration of reactants.

14) The dimensions of rate constant of 2nd order reaction involves
(a) concentration
(b) concentration and time
(c) time only
(d) neither time nor concentration.

15) A zero order reaction A → Products, has rate constant 10-2 mole L-1 s-1. If a process is started with 10 moles of A in a one litre vessel, the number of moles of reactant after 10 minutes will be
(a) 10
(b) 5
(c) 6
(d) 4.
16) For which of the following reactions, the temperature coefficient is maximum?
(a) A → B : Ea = 50 kJ
(b) P → Q : Ea = 40 kj
(c) X → Y : Ea = 60kJ
(d) W → Z : Ea = 80kJ
17) A hypothetical reaction 2p + q → s + r has rate constant as 2.0 × 10-3 mol L-1 s-1. The order of the reaction is
(a) unpredictable
(b) zero
(c) one
(d) two
18) The ratio t7/8 : t1/2 for the first order is
(a) 3
(b) 5
(c) 2
(d) 7
19)The molecularity of the reaction cannot be
(a) 1
(b) 2
(c) 1.5
(d) 3.
20) For the first order reaction, the half-life is independent of
(a) catalyst
(b) temperature
(c) both catalyst and temperature
(d) initial concentration of reactants.
21) DDT on exposure to water decomposes. Half-life = 10 years. How much time will it take for its 90% decomposition?
(a) 50 years
(b) 70 years
(c) 500 years
(d) 700 years.
22) The rate equation for the reaction 2A + B → C is found to be: rate = k [A] [B]. The correct statement inxelation to this reaction is that the
(a) unit of R must be s-1
(b) t1/2 is constant
(c) rate of formation of C is twice the rate of disappearance of A.
(d) value of k is independent of the initial concentration of A and B.

22/07/2023

ELECTOCHEMISTRY
(FOR MAINS, NEET,& 12th)
By(Naveen sir 8860432726)
===========================
1) what are the Functions of the salt bridge?

2) Represent a Galvanic cell in which Zn is oxidised and Cu is reduced.

3) what happens when Applied External potential is more than standard cell potential?

4) Elements A,B,C,D has potential 0.34,-0.11,-0.71, and 0.89 V respectively arrange them in the ease of Oxidation.
5)what is the potential of 'H', if PH is 5

6) what is the relationship between Gibbs energy and equilibrium constant?

7) For the cell reaction Mg +2Ag+ → Mg² +2Ag
a) Represent Galvanic cell
b) what is the direction of current
c) individual reaction of each electrode
d)which is +ve charge electrode?

8) which one is the most durable electroplating of iron, Ni or Zn and why?

9) which device directly converts combustion of fuel into electrical energy?

10) ------ mixture is used in dry cells,as a salt bridge?

11) write the reaction of the lead storage battery, when getting recharged.

12) The potential of Mercury cell is constant throughout its lifetime why?

13) is it possible to set, reaction of corrosion into the Galvanic cell?

14)write the reaction of the fuel cell..

15) what is molar conductivity, and write it's unit

16) what is the product of electrolysis of aq. Agcl

17) Molar conductivity of H2SO4, K2SO4 &
CH3COOK is x,y,z respectively, Calculate molar conductivity of CH3COOH.

18)How many no. Of e- are flows when 1.5A of current passes for 40 min.

19) what is Limiting molar conductivity?

20) How cell constant is related with conductivity and resistance.?. write it's unit.

21) state Kohlaursach Law with example.

22) How much charge is required to reduce dichromate to chromat?

12/10/2022

# Nobel prize in Chemistry
# For click chemistry and bio orthogonal chemistry

10/10/2022

# Fagan rule
# class XI

24/08/2022

Test
HALOALKANES and HALOARENS
Alcohol Phenol and Ether
Class XII

24/08/2022

Assignment
On chemical law
Class XI

24/08/2022

Assignment
Reaction in solution
CLASS XI

24/08/2022

Assignment
Empirical and molecular formula
Mole
Class XI

24/08/2022

Assignment
Periodic Table
Class XI