MCQGeeks
0 : 0 : 1
CBSE
JEE
NTSE
NEET
English
UK Quiz
Quiz
Driving Test
Practice
Diagrams
Games
NEET
NEET Chemistry MCQ
Quiz 1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Q.1
For a zero order reaction A → P t1/2 is ... (k is rate constant)[ BHU 2007]
0%
a)
0%
b)
0%
c)
0%
d)
Explanation
Answer : (a)
Q.2
The calculated spin only magnetic moment of Cr2+ ion is .... ... [NEET 2020]
0%
a) 5.92 BM
0%
b) 2.84 BM
0%
c) 3.87 BM
0%
d) 4.90 BM
Explanation
If hlaf life is 10 min, Initial concentration 10 mole/L half life is 10 min Thus after 10 min concentration [A] becomes 5 mole/L and after 20 min concentration [A] becomes 2.5 mole/Lthen remaining concentration after 20 min will be 2.5 mol L-1 Rate = k[A] Answer: (b)
Q.3
If the rate constant for a first order reaction is k, the time (t) required for the completion of 99% of the reaction is given by: .... [NEET 2019]
0%
a) t = 0.693/k
0%
b) t = 6.909/k
0%
c) t = 4.606/k
0%
d) t = 2.303/k
Explanation
Molecularity is the number of reacting species undergoing simultaneous collision in the elementary or simple reaction. Order is the sum of the powers of the concentration terms in the rate law For simple reaction order is equal to molecularity Answer:(d)
Q.4
For the chemical reaction N2 (g)+ 3H2 (g) ⇋ 2NH (g) The correct option is: [2019]
0%
a)
0%
b)
0%
c)
0%
d)
Explanation
Answer: (c)
Q.5
The correct difference between first- and second-order reactions is that .... [NEET 2018]
0%
a) a first-order reaction can be catalyzed; a second-order reaction cannot be catalyzed
0%
b) the half-life of a first-order reaction does not depend on [A]0; the half-life of a second-order reaction does depend on [A]0
0%
c) the rate of a first-order reaction does not depend on reactant concentrations; the rate of a second-order reaction does depend on reactant concentrations
0%
d) the rate of a first-order reaction does depend on reactant concentrations; the rate of a second-order reaction does not depend on reactant concentrations
Explanation
Answer: (b)
Q.6
When initial concentration of the reactant is doubled, the half-life period of a zero order reaction .... [NEET 2018]
0%
a) is tripled
0%
b) is doubled
0%
c) is halved
0%
d) remains unchanged
Explanation
Order of reaction = sum of exponential terms in rate law = 3/2-1=1/2 Answer: (b)
Q.7
What is the name given to a phenomenon in which both adsorption and absorption takes palace? [ AFMC 2003]
0%
a) Chemisorption
0%
b) Physisorption
0%
c) Desorption
0%
d) Sorption
Explanation
Answer:(d)
Q.8
Which of the following statements are true with respect to adsorption of gas on a solids? [ AFMC 2010] i)The extent of adsorption is equal to kpn according to Freundlich isotherm ii) The extent of adsorption is equal to kp1/n according to Freundlich isotherm iii) The extent of adsorption is equal to (1+bp) / ap according to Langmuir isotherm. iv) At low pressure x/m is directly proportional to the pressure
0%
a) (i) and (iii)
0%
b) (i) and (iv)
0%
c) (ii) and (iii)
0%
d) (ii) and (iv)
Explanation
statement (ii) and (iv) are correct remaining false Answer: (d)
Q.9
The equation for freundlich adsorption isotherm is .. [ AFMC 2007]
0%
a) x/m = kp1/n
0%
b) x = mkp1/n
0%
c) x/m = kpn-1
0%
d) all of these
Explanation
same equation but indifferent mathematical form Answer: (d)
Q.10
The coagulation power of an electrolyte for As2S3 decreases in the order. [ AFMC 2011]
0%
a) Na+, Al3+, Ba2+
0%
b) Cl-, SO42-, PO43-
0%
c) Al3+, Ba2+, Na+
0%
d) PO43-, SO42-, Cl-
Explanation
As2S3 is negative sol. required ion will be positive Now higher is the charge on ions higher is coagulation power and lower flocculation value, Answer: (c)
Q.11
Surface water contains [ AFMC 2003]
0%
a) suspended impurities
0%
b) organic compound
0%
c) salt
0%
d) salt and organic compounds
Explanation
Answer:(a)
Q.12
The dispersed phase, dispersion medium and nature of colloidal solution ( lyophobic or lyophilic ) of 'gold sol' respectively are ..[ AMMC 2008]
0%
a) solid, solid, lyophobic
0%
b) liquid,liquid, lyophobic
0%
c) solid, liquid, lyophobic
0%
d) solid, liquid, lyophilic
Explanation
In case of 'Gold sol' we have Dispersed phase = Solid Dispersion medium = Liquid Gold sol is lyophobic colloid. i.e (c) is correct answer Answer: (c)
Q.13
The potential energy diagram for a reaction R → P is given below ΔH of the reaction corresponds to the energy ... [ AIIMS 2003]
0%
a) x
0%
b) y
0%
c) z
0%
d) (x+y)
Explanation
ΔH = energy of product - energy of reactant In graph difference is show as x Answer : (a)
Q.14
In order to react, a molecule, at the time of collision, must possess a certain amount of energy known as
0%
a) free energy
0%
b) kinetic energy
0%
c) internal energy
0%
d) threshold energy
Explanation
Answer : (d)
Q.15
In a first order reaction A → B, if k is rate constant and initial concentration of the reactant A is 0.5M then half-life is ...[ CBSE 2007]
0%
a)
0%
b)
0%
c)
0%
d)
Explanation
From formula 0.693 = ln2 Answer : (c)
Q.16
Rate of a chemical reaction can be kept constant by ...[ BHU 1993]
0%
a) stirring the compounds
0%
b) keeping the temperature constant
0%
c) both a and b
0%
d) none of the above
Explanation
From the given option only temperature can alter the rate. If temperature is kept constant, the rate of reaction will be constant Answer : (b)
Q.17
Assertion The rate of reaction sometimes does not depends on concentration Reason The order of reaction can be zero
0%
a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion
0%
b) The Assertion and Reason are true but Reason is not correct explanation of Assertion
0%
c) Assertion is true but, Reason is false
0%
d) Assertion is false but, Reason is true
Explanation
A reaction is said to be of zero order if its rate is independent of the concentration of the reactants, The rates of these zero-order reactions do not vary with increasing nor decreasing reactants concentrations. This means that the rate of the reaction is equal to the rate constant, k , of that reaction. The rate constant k varies with temperature, and is also affected by the addition of a catalyst Now A first-order reaction has a rate proportional to the concentration of one reactant. Answer : (a)
Q.18
For zero order reaction ..[ EAMCET 1990]
0%
a) t1/2 ∝ Ro
0%
b) t1/2 ∝ 1/Ro
0%
c) t1/2 ∝ Ro2
0%
d) t1/2 ∝ 1/Ro2
Explanation
Answer : (a)
Q.19
What is the unit of rate of reaction whose rate law is given as Rate = k[A]3/2[B]-1
0%
a) sec-1
0%
b) mol L-1 s-1
0%
c) mol1/2L-1/2s-1
0%
d) L1/2mol-1/2s-1
Explanation
Order of reaction = Sum of power of concentration = 3/2 -1 = 1/2 From general formula for unit for k here n= 1/2 Answer : (c)
Q.20
Half-life of a first order reaction in 10 min. What % of reaction will be completed in 100 min? [ AFMC 2002 ]
0%
a) 25%
0%
b) 99.9%
0%
c) 75%
0%
d) 0.0975%
Explanation
at end of 10 min = 50% reactant pending at end of 20 min = 25% reactant pending at end of 30 min = 12.5% reactant pending at end of 40 min = 6.25% reactant pending at end of 50 min = 3.125% reactant pending at end of 60 min = 1.562% reactant pending at end of 70 min = 0.781% reactant pending at end of 80 min = 0.39% reactant pending at end of 90 min = 0.195% reactant pending at end of 100 min = 0.0975% reactant pending ∴ Completed = 100 -0.0975 = 99.9 % Answer : (b)
Q.21
For a reaction, 2A + B → C + D, the concentration of B is kept constant and that of A is tripled the new rate of reaction will be
0%
a) nine times
0%
b) three times
0%
c) same
0%
d) zero
Explanation
Answer : (a)
Q.22
The molecularity of a reaction is ...[ AFMC 2001]
0%
a) always two
0%
b) same as its order
0%
c) different than the other
0%
d) may be same or different as compared to order
Explanation
Answer : (d)
Q.23
The rate of the reaction, 3A + 2B → Product is given by the rate expression: Rate = k[A][B]2 If A is taken in excess, the order of the reaction would be
0%
a) 1
0%
b) 2
0%
c) 3
0%
d) 5
Explanation
When A is taken in excess, its concentration will become constant, the law may, therefore, be given as Rate = k'[B]2 or der =2 Answer : (b)
Q.24
For a given reaction of first order, it takes 20 minutes for the concentration to change from 1.0M to 0.6 M. The time required for the concentration to drop from 0.6M to 0.36M will be i ...
0%
a) more than 20 minutes
0%
b) less than 20 minutes
0%
c) equal to 20 minutes
0%
d) infinity
Explanation
First find k using following formula R0= 1.0M and R = 0.6, t= 20 min Then use same formula to find t, R0 = 0.6M and R =0.36 M Answer : (c)
Q.25
The half-life period of first order reaction is 10 minutes. the time required for the concentration of the reactant to change from 0.08M to 0.02M is ...
0%
a) 10 min
0%
b) 20 min
0%
c) 30 min
0%
d) 40 min
Explanation
Reaction is first order use following formula Answer : (b)
Q.26
The rate constant for a first order reaction is 6.909 min-therefore, the time required in minutes for the participation of 75% of the initial concentration is
0%
a) (2/3)log2
0%
b) (2/3)log4
0%
c) (3/2)log2
0%
d) (3/2) log4
Explanation
half-life of first order reaction is Since t3/4 = 2× t1/2 thus option "a" is correct Answer : (a)
Q.27
The rate constant k1 and k2 for two different reactions are 1016e-2000/T and 1015e-1000/T, respectively. The temperature at which k1 = k2 is ..[ CBSE 2008]
0%
a) 2000K
0%
b) 1000k
0%
c) (1000/2.303)k
0%
d) (2000/2.303)k
Explanation
1016e-2000/T and 1015e-1000/T Answer : (c)
Q.28
For which of the following reactions k310/k300 would be maximum?
0%
a) A + B → C; Ea = 50 kJ
0%
b) X + Y → Z; Ea = 40 kJ
0%
c) P + Q → R; Ea = 60 kJ
0%
d) E + F → G; Ea = 100 kJ
Explanation
From the formula From above equation, increase in rate constant is maximum for the reaction having maximum activation energy Answer : (d)
Q.29
For a reaction, the threshold energy is equal to
0%
a) activation energy + initial potential energy of reactants
0%
b) activation energy - initial potential energy of reactants
0%
c) activation energy
0%
d) initial potential energy of reactants
Explanation
Answer : (a)
Q.30
For which of the following reactions, the half-life is directly proportional to the initial concentration of the reactant? [ MPPMT 2006]
0%
a) zero order
0%
b) First order
0%
c) Second order
0%
d) Third order
Explanation
Answer : (a)
0 h : 0 m : 1 s
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Report Question
×
What's an issue?
Question is wrong
Answer is wrong
Other Reason
Want to elaborate a bit more? (optional)