FINAL TOUCH REVISION
FOR
IIT JEE MAIN
PHYSICAL & INORGANIC
CHEMISTRY
BY
PRINCE SINGH
ATOMIC STRUCTURE
CHEMICAL KINETICS
ETOOSINDIA
INDIA’S NO. 1 ONLINE COACHING
Plot No. 38, Near Union Bank of India, Rajeev Gandhi Nagar,
Kota, Rajasthan – 324005 Mob. : 9214233303
ETOOSINDIA FTR BY P.S. SIR
INDIA’S NO. 1 ONLINE COACHING
x
1. An electron in an atom jumps in such a way that its kinetic energy changes from x to . The change in its potential
9
energy will be-
x 16x 9
(A) (B) (C) 9x (D) x
9 9 16
Ans. (A)
2. The potential energy of an electron in He+ ion is – 12.09 eV. Indicate in which excited state, the electron is present–
(A) First (B) Second (C) Third (D) Fourth
Ans. (B)
3. An electron has velocity x ms–1. For a proton to have the same de-Broglie wavelength, the velocity will be
approximately –
1840 x
(A) (B) (C) 1840x (D) x
x 1840
Ans. (B)
4. Photoelectric emission is observed from a surface for frequencies 1 and 2 of incident radiations
(1 > 2). If the maximum K.E. of photoelectrons in two cases are in the ratio of 2 : 1, then threshold frequency 0 is
given by -
2 1 2 1 2 2 2 1
(A) (B) (2 1) (C) (2 1) (D) 2 1
2
Ans. (C)
5. Which excited state of Be3+ has the same orbit radius as that of the ground state of hydrogen atom ?
(A) 3 (B) 2 (C) 4 (D) 1
Ans. (D)
6. If uncertainty in position and momentum are equal then uncertainty in velocity is :
1 h h 1 h h
(A) (B) (C) (D)
m 2m 2
Ans. (C)
7. The wavelengths of electrons waves in two orbits is 3 : 5. The ratio of kinetic energy of electrons will be :
(A) 25 : 9 (B) 5 : 3 (C) 9 : 25 (D) 3 : 5
Ans. (A)
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Kota, Rajasthan – 324005 Mob. : 9214233303
ETOOSINDIA FTR BY P.S. SIR
INDIA’S NO. 1 ONLINE COACHING
8. Which of the following graphs is incorrect ?
v v v v
(A) (B) (C) (D)
n 1/n z n
Ans. (D)
9. The transitions from the state n = 4 to n = 3 in a H like atom results in UV radiation. The infra-red radiations will be
obtained in the transition :
(A) 2 1 (B) 3 2 (C) 4 2 (D) 5 4
Ans. (D)
10. An electron, a proton and an alpha particle have kinetic energies of 16E, 4E and E respectively. What is the
qualitative order of their de-Broglie wavelengths ?
(A) e > p = (B) p = > e (C) p > e > (D) < e >> p
Ans. (A)
11. The ionization energy of hydrogen atom (in the ground state) is x kJ. The energy required for an electron to jump
from 2nd orbit to the 3rd orbit will be :
(A) x/6 (B) 5x (C) 7.2x (D) 5x/36
Ans. (D)
12. If the shortest wavelength of H atom in Lyman series is x. then longest wavelength in Balmer series of He+ is -
9x 36x x 5x
(A) (B) (C) (D)
5 5 4 9
Ans. (A)
13. If 0 be the permittivity of vaccum and r be the radius of orbit of H-atom in which electron is revolving then velocity
of electron is given by :
e 4 0 rm 4 0 rm
(A) v (B) v e 4 0 rm (C) v (D) v
4 0 rm e e2
Ans. (A)
14. If the energy of H-atom in the ground state is –E, the velocity of photo-electron emitted when a photon having
energy EP strikes a stationary Li2+ ion in ground state, is given by :
2( E p E ) 2( E p 9E ) 2( E p 9 E ) 2(E p 3E )
(A) v (B) v (C) v (D) v
m m m m
Ans. [C]
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Kota, Rajasthan – 324005 Mob. : 9214233303
ETOOSINDIA FTR BY P.S. SIR
INDIA’S NO. 1 ONLINE COACHING
15. In the following two figures (2) is plotted against (r), the distance from nucleus
2 2
(A) Distance from nucleus (B) Distance from nucleus
(A) Both (A) and (B) are for 1s
(B) Both A & B are for 2s
(C) A is for 1s, & B is for 2s
(D) A is for 2s & (B) is for 1s
Ans. (C)
16. Statement-1 : If the activation energy of reaction is zero temperature will have no effect on the rate constant
Statement-2 : Lower the activation energy faster is the reaction
(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1.
(B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1.
(C) Statement-1 is True, Statement-2 is False.
(D) Statement-1 is False, Statement-2 is True.
Ans. (B)
17. Statement-1 : Half life of a certain radioactive element is 100 days. After 200 days, fraction left undecaye will
be 25%.
Statement-2 : , where symbols have standard meaning.
(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1.
(B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1.
(C) Statement-1 is True, Statement-2 is False.
(D) Statement-1 is False, Statement-2 is True.
Ans. (A)
18. In the following reaction : xA yB
d[ A ] d[B]
log dt = log dt + 0.3
where –ve sign indicates rate of disappearance of the reactant. Thus, x : y is :
(A) 1 : 2 (B) 2 : 1 (C) 3 : 1 (D) 3 : 10
Ans. (B)
19. aA + bB Product, Rate = k [A]a [B]b . If concentration of A is doubled, rate becomes four times. If
concentration of B is made four times, rate is doubled. What is relation between rate of disappearance of A and that
of B ?
(A) – {d [A] / dt} = – {d [B] / dt} (B) – {d [A] / dt} = – {4 d [B] / dt}
(C) – {4 d [A] / dt} = – {d [B]/ dt} (D) None of these
Ans. (B)
Plot No. 38, Near Union Bank of India, Rajeev Gandhi Nagar, Page # 4
Kota, Rajasthan – 324005 Mob. : 9214233303
ETOOSINDIA FTR BY P.S. SIR
INDIA’S NO. 1 ONLINE COACHING
20. The rate constant of the reaction A 2B is 1.0 × 10–3 mol lit–1 min–1, if the initial concentration of A is 1.0 mole lit–
1 what would be the concentration of B after 100 minutes.
(A) 0.1 mol lit–1 (B) 0.2 mol lit–1 (C) 0.9 mol lit–1 (D) 1.8 mol lit–1
Ans. (B)
21. What will be the order of reaction for a chemical change having log t50% vs log a curves as :
(where a = initial concentration)
(A) 1 (B) 2 (C) 3 (D) 4
22. Match the graphical study with the order of the reactions :
I : Rate II : Half life III : (a – x)–1
I II III I II III
(A) A B C (B) B C A
(C) C B A (D) C A B
Ans. (D)
23. Which of the following statements about the arrhenius equation are INCORRECT ?
(A) The pre exponential factor become equal to the rate constant of the reaction at temperature T
(B) When the activation energy of the reaction zero, the rate becomes independent of temperature.
(C) The term e–Ea/RT represents the fractions of the molecules having energy is excess of the threshold value.
(D) On raising temperature , rate constant of the reaction of greater activation energy increases less rapidly than
that of the reaction of smaller activation energy.
Ans. (D)
24. A hypothetical reaction X2 + Y2 2XY follows the mechanism given below..
X2 X + X [Fast]
X + Y2 XY + Y [Slow]
X + Y XY [Fast]
The order of overall reaction is
(A) 2 (B) 1 (C) 1.5 (D) Zero
Ans. (C)
Plot No. 38, Near Union Bank of India, Rajeev Gandhi Nagar, Page # 5
Kota, Rajasthan – 324005 Mob. : 9214233303
ETOOSINDIA FTR BY P.S. SIR
INDIA’S NO. 1 ONLINE COACHING
25. The rate of a first order reaction is 0.04 mole litre–1 s–1 at 10 minutes and 0.03 mol litre–1 s–1 at 20 minutes after
initiation. The rate constant of the reaction is-
take [ log 4= 0.6 and log 3 = 0.5 ]
(A) 0.02303 (B)0.04606 (C) 0.2303 (D) 0.4606
Ans. (A)
26. The rate constant for the reaction
2N2O5 4NO2 + O2
is 3.0 × 10–5 sec–1, if the rate is 2.4 × 10–5 mol litre–1 sec–1, then the concentration of N2O5 (in mol litre–1) is.
(A) 1.4 (B) 1.2 (C) 0.004 (D) 0.8
Ans. (D)
27. Consider the reaction:
Cl2(aq) + H2S(aq) S(s) + 2H+(aq) + 2Cl–(aq)
The rate equation for this reaction is
rate = k[Cl2][H2S]
Which of these mechanisms is/are consistent with this rate equation ?
A. Cl2 + H2S H+ + Cl– + Cl+ + HS– (slow)
Cl+ + HS– H+ + Cl– + S(fast)
B. H2S H+ + HS– (fast equilibrium)
Cl2 + HS– 2Cl– + H+ + S(slow)
(A) A only (B) B only (C) Both A and B (D) Neither A nor B
Ans. (A)
28. H2 gas is adsorbed on the metal surface like tungsten. This follows ........ order reaction -
(A) Third (B) Second (C) Zero (D) First
Ans. (C)
29. In a first order reaction, the concentration of the reactant, decreases from 0.16 M to
0.8 M in 15 minutes. The time taken for the concentration to change from 0.1 M to
0.025 M is
(A) 7.5 min (B) 15 min (C) 30 min (D) 60 min
Ans. (C)
30. The mechanism of the reaction 2NO + O2 2NO2 is :
k1
NO + NO N2O2 (fast) ;
k–1
N2O2 + O2 k2 2NO2 (slow)
The rate constant of the reaction is
k
(A) k2 (B) k2k1 (k–1) (C) k2k1 (D) k2 1
k 1
Ans. (D)
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Kota, Rajasthan – 324005 Mob. : 9214233303
