According to Born-Haber's cycle, the enthalpy of the formation of ionic compounds can be determined. The formation of NaCl involves the following steps :

(I) \(Na(s)\xrightarrow[Energy \ of \ sublimation]{S} \ Na(g)\)     

(II) \(Na(g)\xrightarrow[Ionisation \ potential]{I} \ Na^{+}(g) \ + \ e^{-}\)

(III) \(Cl_{2}(g)\xrightarrow[Bond \ dissociation \ energy]{D} \ 2Cl(g)\)

(IV) \(Cl(g) \ + e^{-}\xrightarrow[Electron \ affinity \ energy]{E} \ Cl^{-}(g)\)

 (V) \(Cl^{-}(g) \ + Na^{+}(g)\xrightarrow[Lattice \ energy \ energy]{U} \ NaCl(s)\)

The enthalpy of formation of NaCl will be :

1. Hf=S+I-D2-E-U

2. Hf=S+I+D2-E-U

3. Hf=-S-I-D+E2+U

4. Hf=-S-I-D-E2-U

Subtopic:  Hess's Law |
 71%
From NCERT

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.


Which of the following is the least volatile?
     

1. HCN                     
2. HF        
3. H2O                     
4. CS2

Subtopic:  van der Waal Force & Hydrogen Bonding |
From NCERT

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.


A : Tetracyanomethane

B : Carbondioxide

C : Benzene

D : 1,3-Buta-di-ene

Ratio of σ and π bonds is in order :       

1. A = B < C < D           

2. A = B < D < C           

3. A = B = C = D           

4.  C < D < A < B

Subtopic:  Covalent Bond |
 64%
From NCERT

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.


advertisementadvertisement

The maximum number of 90° angles between bond pair-bond pair of electrons is observed in:

1.  sp3d2-hybridization.            

2.  sp3d-hybridization.

3.  dsp2-hybridization.             

4.  dsp3-hybridization.

Subtopic:  Hybridisation |
 73%
From NCERT

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.


The ion that has a trigonal planar shape is: 

1. SO32-

2. PO43-

3. CN-

4. CO32-

Subtopic:  Hybridisation | V.S.E.P.R & V.B.T |
 75%
From NCERT

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.


Which of the following molecules or ions is not linear ?               

1. BeCl2                 

2. ICl2-        

3. CS2                     

4. ICl2+

Subtopic:  V.S.E.P.R & V.B.T |
 60%
From NCERT

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.


advertisementadvertisement

Which reaction involves a change in the electron-pair geometry for the underlined atom?

1. BF3 +F-BF4- 

2. NH3+H+NH4+

3. 2SO2+O22SO3 

4. H2O+H+H3O+   

Subtopic:  V.S.E.P.R & V.B.T |
 73%
From NCERT

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.


The correct order of increasing s-character (in percentage) in the hybrid orbitals of following molecules/ion is :

(i) CO32-   (ii) XeF4     (iii) I3-       (iv) NCl3   (v) BeCl2

1.  ii < iii < iv < i < v

2. ii < iv < iii < v < i

3. iii < ii < i < v < iv        

4. ii < iv < iii < i < v

Subtopic:  Hybridisation |
 70%
From NCERT

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.


Which of the following condition show linear geometry (b.p. = Bond pair, I.p. = Lone pair) :

(a)  Molecule in which central atom show sp3d hybridisation and contain 3 b.p. and 2 l.p.

(b)  Any diatomic molecule

(c)  Tri-atomic molecule in which central atom has 2 l.p and 2σ b.p.

(d)  Molecule in which central atom has 2σ b.p. and 2π b.p. and contain no. l.p.

1. a, b                       2. b, d

3. a, c, d                   4. a, b, c, d

Subtopic:  V.S.E.P.R & V.B.T |
 69%
From NCERT

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.


advertisementadvertisement

Which is non-angular species :

1. I3+                2. ClO2-    

3. SO2              4. I3-  

Subtopic:  V.S.E.P.R & V.B.T |
 63%
From NCERT

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 20 chapters you need to be enrolled in MasterClass Course.