11th Standard Chemistry English Medium Free Online Test One Mark Questions with Answer Key 2020 - Part Seven

11th Standard

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Chemistry

Time : 00:25:00 Hrs
Total Marks : 25

25 x 1 = 25
1. Assertion: The atomic masses of most of the elements. are in the fraction.
Reason:  The atomic mass represents the ratio of the average mass of the atom to one avogram.

(a)

Both assertion and reason are correct and the reason is the correct explanation for assertion

(b)

Both assertion and reason are correct but the reason is not the correct explanation for an assertion

(c)

Assertion is true but reason are false

(d)

Both assertion and reason are false

2. One mole of CO2 contains:

(a)

6.023 x 1023atoms of C

(b)

6.023 x 1023atoms of O

(c)

18.1 x 1023molecules of CO2

(d)

3g atoms of CO2

3. Which of the following electronic configuration represent the element in ground state?

(a)

1s22s12p1

(b)

1s22s22p1

(c)

1s22s12px12py12pz1

(d)

1s22s22p63s23px13py13pz13d1

4. J. J. Thomson's cathode ray experiment revealed that atoms consist of

(a)

electrons

(b)

protons

(c)

neutrons

(d)

photons

5. The maximum number of electrons that can be accommodated in N shell is_____________

(a)

8

(b)

18

(c)

32

(d)

36

6. The idea of stationary orbits was first given by_________.

(a)

Rutherford

(b)

J.J. Thomson

(c)

Niels Bohr

(d)

Max Planck

7. The following tame shows the successive molar ionisation energy (kJ mol-1) of five elements A to E. Which of two elements are most likely to be in the same group of the periodic table

Element Ionisation Energy (K mol-1)
1st 2nd 3rd 4th
A 2080 4000 6100 9400
B 500 4600 6900 9500
C 740 1500 7700 10500
D 580 1800 2700 11600
E 420 3100 4400 5900
(a)

C and D

(b)

D and E

(c)

B and D

(d)

B and E

8. The chemical symbol of carbon and cobalt are______

(a)

Ca and CO

(b)

Ca and Cl

(c)

C and CO

(d)

Cr and Cb

9. Among halogens, the correct order of amount of energy released in electron gain is:

(a)

F>CI>Br>I

(b)

F<CI<Br<I

(c)

F<CI>Br>I

(d)

F<CI<Br>I

10. Statement-I: Ionization enthalpy of Be is greater than that of B.
Statement-:II: The nuclear charge of B is greater than that of Be.

(a)

Statement-I and II are correct and statement-II is the correct explanation of statement-I.

(b)

Statement-I and statement-II are correct but statement-II is not the correct explanation of statement-I.

(c)

Statement-I is correct but statement-II is wrong.

(d)

Statement-I is wrong but statement-II is correct.

11. The electronic configuration of the atom having maximum difference in first and second ionisation energies is

(a)

1s2, 2s2, 2p6, 3s1

(b)

1s2, 2s2, 2p6, 3s2

(c)

1s2, 2s2, 2p6, 3s2, 3s2, 3p6, 4s1

(d)

1s2, 2s2, 2p6, 3s2, 3p1

12. Hydrogen burns in air with a - flame.

(a)

light blusish

(b)

yellow

(c)

green

(d)

none of these

13. In which of the following compounds does hydrogen has an oxidation state of -1?

(a)

CH4

(b)

NH3

(c)

HCl

(d)

CaH2

14. Heavy water is __________

(a)

De-mineralized water

(b)

De-ionized water

(c)

ordinary water containing dissolved salts of heavy metals.

(d)

The compound of heavier isotope of hydrogen with oxygen.

15. A example of covalent hydride is ____________

(a)

CaH2

(b)

CH4

(c)

TiH

(d)

all the above

16. Compounds of alkaline earth metals are less soluble in water than the corresponding alkali metals salts due to :

(a)

their increased covalent character

(b)

high lattice energy

(c)

their high ionization energy

(d)

none of the above

17. Which one of the following alkaline earth metal is not readily attacked by acids?

(a)

Magnesium

(b)

Calcium

(c)

Beryllium

(d)

Strontium

18. Which one of the following is used in toothpaste, shampoo and hair products?

(a)

Plaster of paris

(b)

Limestone

(c)

Quick lime

(d)

Gypsum

19. Which one of the following metal act as co-factor in phosphate transfer of ATP by enzymes?

(a)

Calcium

(b)

Beryllium

(c)

Magnesium

(d)

Sodium

20. Which of the following gas is present maximum in atmospheric air?

(a)

O2

(b)

N2

(c)

H2

(d)

21. Heat of combustion of methane is ------- KJ/mol.

(a)

-87.78

(b)

+87.78

(c)

-394.55

(d)

+394.55

22. The condition for standard free energy is _______

(a)

298 K, 1 atm

(b)

273 K, 1 atm

(c)

2980 C, 5 atm

(d)

25 K, 1atm

23. For the formation of Two moles of SO3(g) from SO2 and O2, the equilibrium constant is K1. The equilibrium constant for the dissociation of one mole of SO3 into SO2 and O2 is

(a)

$1/K_1$

(b)

$K_1^2$

(c)

$({1\over K_1})^{1/2}$

(d)

${K_1\over 2}$

24. Assertion: Oxygen molecule is paramagnetic.
Reason: It has two unpaired electron in its bonding molecular orbital.

(a)

both assertion and reason are true and reason is the correct explanation of assertion

(b)

both assertion and reason are true but reason is not the correct explanation of assertion

(c)

assertion is true but reason is false

(d)

Both assertion and reason are false

25. The name of C2F4Cl2 is ___________

(a)

Freon – 112

(b)

Freon – 113

(c)

Freon – 114

(d)

Freon – 115