#### 11th Standard Chemistry Chemical bonding English Medium Free Online Test One Mark Questions 2020 - 2021

11th Standard

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Chemistry

Time : 00:20:00 Hrs
Total Marks : 20

20 x 1 = 20
1. In which of the following Compounds does the central atom obey the octet rule?

(a)

XeF4

(b)

AlCl3

(c)

SF6

(d)

SCl2

2. 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

3. In ClF3, NF3 and BF3 molecules the chlorine, nitrogen and boron atoms are

(a)

sp3 hybridised

(b)

sp3 ,sp3 and sp2 respectively

(c)

sp2 hybridised

(d)

sp3d, sp3 and sp hybridised respectively

4. Which of these represents the correct order of their increasing bond order

(a)

$C_2 (b) \(C_2^{2-} (c) \(O_2^{2-} (d) \(O_2^{2-} 5. The correct order of O-O bond length in hydrogen peroxide, ozone and oxygen is (a) H2O2 > O3 >O2 (b) O2 > O3 > H2O2 (c) O2 > H2O2 > O3 (d) O3 > O2 > H2O2 6. Bond order of a species is 2.5 and the number of electons in its bonding molecular orbital is formd to be 8 The no. of electons in its antibonding molecular orbital (a) three (b) four (c) Zero (d) cannot be calculated form the given unformation 7. Pick out the incorrect statement from the following (a) Sp3 hybrid orbitals are equivalent and are at an angle of 109o 28' with each other (b) dsp2 hybrid orbitals are equivalent and bond angle between any two of them is 90o (c) All five sp3d hybrid orbitals are not equivalent out of these five sp3d hybrid orbitals, three are at an angle of 120o, remainir two are perpendicular to the plane containing the other three (d) none of these 8. Which of the following molecule has no dative bond? (a) CO (b) \({ SO }_{ 4 }^{ 2- }$

(c)

${ CO }_{ 3 }^{ 2- }$

(d)

None of these

9. Which among the following molecule obeys octet rule?

(a)

NO

(b)

NO2

(c)

N2O3

(d)

ClO2

10. Calculate the formal charge on C-atom in carbonate ion.

(a)

-1

(b)

0

(c)

+1

(d)

+2

11. Pick out the molecule having double bond.

(a)

O2

(b)

N2

(c)

He2

(d)

H2

12. The correct sequence of increasing covalent character is

(a)

LiCl < NaCl <BeCl2

(b)

NaCl < LiCl < BeCl2

(c)

BeCl2<LiCl<NaCl

(d)

<NaCI < LiCI

13. The formula of the compound is A2B3. The number of electrons in the outermost orbits of A and B respectively are,

(a)

3 and 6

(b)

3 and 2

(c)

2 and 3

(d)

5 and 2

14. Which compound has planar structure?

(a)

XeF4

(b)

XeOF2

(c)

XeO2F2

(d)

XeO4

15. The correct order of increasing bond angles in the following triatomic species is:

(a)

${ NO }_{ 2 }^{ + }$< NO2 <${ NO }_{ 2 }^{ - }$

(b)

${ NO }_{ 2 }^{ - }$< NO2 <${ NO }_{ 2 }^{ + }$

(c)

${ NO }_{ 2 }^{ - }$<${ NO }_{ 2 }^{ + }$< NO2

(d)

${ NO }_{ 2 }^{ + }$< ${ NO }_{ 2 }^{ - }$<NO2

16. H2O is polar, whereas BeF2 is not It is because

(a)

The electronegativity of F is greater than that of O.

(b)

H2O involves hydrogen bonding whereas BeF2 is a discrete molecule

(c)

H2O is linear and BeF2 is angular

(d)

H2O is angular and BeF2 is linear

17. Which of the following statements are correct with respect to bond order?
(i) Bond order of N2 is 3.5
(ii) Bondorder of O2 is 2
(iii) Bond order of NO+ is 3.0
(iv) Bond order of NO is 2.5

(a)

Only (i)

(b)

(i), (ii), (iv)

(c)

(ii), (iii), (iv)

(d)

(i), (ii), (iii), (iv).

18. Statement I: N2, CO and CN- are having same bond order.
Statement II : Isoelectronic species always have same bond order.

(a)

Both statement I and II are true and statement II explains statement I.

(b)

Both statement I and II are true but statement I does not explain statement II.

(c)

Statement I is true, but statement II is false

(d)

Both-statement I and II are false

19. Identify the incorrect statement with respect to hybridisation.

(a)

Hybridisation is intermixing of orbitals of nearly equal energies.

(b)

Shape of molecule depends upon type of hybridisation only.

(c)

Hybrid orbitals are identical in all aspects.

(d)

Hybrid orbitals can form $\sigma$ and $\pi$ bond

20. The hybrididsation of S in SO2 is

(a)

sp

(b)

Sp2

(c)

sp3

(d)

None of these