Features of MOT

Q.

Calculate the bond order of $O_{\mathit{2}}^{\mathit{+}}$

Q. which bond has greater energy sigma or pi bond?

Q. why the bond order of CO+ is 3.5 and not 2.5 ?

Q. Paramagnetism is exhibited by the molecules which:

1. are not attracted by magnetic field
2. contains only paired electrons
3. carries a positive charge
4. contains unpaired electrons

Q.

In PCl₅, the three P- Cl bonds in plane are called as

1. Sigma bonds

2. Equatorial bonds

3. Semi - planar bonds

4. Axial bonds

Q. 23. The wave length of the third line of the Balmer series for a hydrogen atom is

Q. Bond order depends on the number of bonding and anti-bonding orbitals. The bond order can never have:

1. A negative value
2. An integral value
3. Assume any positive, or an integral, or a fractional value including zero
4. a non zero value

Q. The bond dissociation energies of X2, Y2 and XY are in the ratio of 1:0.5:1 . ∆H for the formation of XY is -200KJ mol-1 . The bond dissociation energy of X2 will be

Q. More than One Answer Type
एक से अधिक उत्तर प्रकार के प्रश्न

Analyse the following graphs for a given orbital and select the correct statement(s).

दिए गए कक्षक के लिए निम्नलिखित ग्राफ का विश्लेषण कीजिए तथा सही कथन/कथनों का चयन कीजिए।

1. ψ is maximum at nucleus but P(r) is zero because of negligible volume component
   
   नाभिक पर ψ अधिकतम होता है लेकिन नगण्य आयतन घटक के कारण P(r) शून्य होता है
2. Given orbital has 1 radial node
   
   दिए गए कक्षक में 1 त्रिज्य नोड है
3. Given orbital has zero angular nodes
   
   दिए गए कक्षक में कोणीय नोड शून्य है
4. Given orbital is 2s
   
   दिया गया कक्षक 2s है

Q. Match the following:$\begin{array}{cc}\text{Column-I}& \text{Column -II}\\ {\text{(a) O}}_2^{2-}& \text{(p)Bond order = 0.5}\\ \text{(b) CO}& \text{(q)Bond order = 3}\\ {\text{(c)NO}}^{+}& \text{(r)Bond order = 1}\\ {\text{(d)He}}_2^{+}& \text{(s)Paramagnetic}\\ & \text{(t) Diamagnetic}\end{array}$

1. $(a-r,t)$
   $(b-q,t)$
   $(c-q,t)$
   $(d-p,s)$
2. $(a-q,t)$
   $(b-r,t)$
   $(c-r,t)$
   $(d-p,s)$
3. $(a-r,s)$
   $(b-q,s)$
   $(c-r,s)$
   $(d-r,t)$
4. $(a-q,s)$
   $(b-p,s)$
   $(c-p,t)$
   $(d-r,t)$

Q. Using s, p, d notations, describe the orbital with the following quantum numbers.
(a) n=1, $l$=0;
(b) n = 3; $l$=1;
(c) n = 4; $l$ =2;
(d) n=4; $l$=3.

Q.

The number of π and σ bonds present in H₂C=CHCH=CHCH₂ are:

1. 2, 12

2. 11, 2

3. 2, 11

4. 12, 2

Q.

A. H${}_2$ 1. 2

B. N${}_2$ 2. 1

C. O${}_2$ 3. 3

D.H${}_2$${}^{-}$ 4. 0.5

The correct match of bond order is

1. A - 2, B - 3, C - 4, D - 3

2. A - 2, B - 1, C - 3, D - 4

3. A - 1, B - 2, C - 3, D - 4

4. A - 2, B - 3, C - 1, D - 4

Q. among F2, Cl2, O2 and N2 which has least bond dissociatuon enthalpy

Q. Write the important conditions required for the linear combination of atomic orbitals to form molecular orbitals :

Q. In calculating the number of spectral lines when to apply these two formulas- 1. (n2-n1)(n2-n1+1)/2 2. (n2-n1)

Q. The radial wave equation for hydrogen atom is
$\Psi =\frac{1}{16\sqrt{\pi }}{\left(\frac{1}{a_0}\right)}^{3/2}\left[(x-1)(x^2-8x+12)\right]e^{-x/2}$

1. $a_0,3a_0$
2. $\frac{a_0}{2},3a_0$
3. $\frac{a_0}{2},a_0$
4. $\frac{a_0}{2},4a_0$

Q.

Use molecular orbital theory to explain why the Be₂ molecule does not exist.

Q. Which of the following statements is correct regarding molecular orbital theory (MOT)?

1. Energy of bonding orbital is less than that of anti-bonding orbital
2. Energy of bonding orbital is more than that of anti-bonding orbital
3. Bonding orbitals are monocentric
4. Bonding orbitals follow (n+ l) rule
   

Q. (i) Write the electronic configurations of the following ions: (a) $H^{-}\left(b\right){Na}^{+}\left(c\right)O^{2-}\left(d\right)F^{-}$.
(ii) What are the atomic numbers of elements whose outermost electrons are represented by $\left(a\right){3s}^1\left(b\right){2p}^3$ and $\left(c\right){3d}^1$ ?
(iii) Which atoms are indicated by the following configurations ?
(a) $\left[He\right]2s^1$ (b) $\left[Ne\right]{3s}^2{3p}^3$ (c) $\left[Ar\right]{4s}^2{3d}^1$

Q. why trans isomers are non polar while cis isomers are polar?

Q. Match the following:$\begin{array}{cc}\text{Column-I}& \text{Column -II}\\ {\text{(a) O}}_2^{2-}& \text{(p)Bond order = 0.5}\\ \text{(b) CO}& \text{(q)Bond order = 3}\\ {\text{(c)NO}}^{+}& \text{(r)Bond order = 1}\\ {\text{(d)He}}_2^{+}& \text{(s)Paramagnetic}\\ & \text{(t) Diamagnetic}\end{array}$

1. $(a-r,t)$
   $(b-q,t)$
   $(c-q,t)$
   $(d-p,s)$
2. $(a-q,t)$
   $(b-r,t)$
   $(c-r,t)$
   $(d-p,s)$
3. $(a-r,s)$
   $(b-q,s)$
   $(c-r,s)$
   $(d-r,t)$
4. $(a-q,s)$
   $(b-p,s)$
   $(c-p,t)$
   $(d-r,t)$

Q.

The species having bond order different from that in CO is:

1. 
2. 
3. 
4. 

Q. According to Molecular Orbital Theory

1. $C_2^{2-}$ is expected to be diamagnetic
2. $O_2^{2+}$ expected to have a longer bond length than $O_2$
3. $N_2^{+}$ and $N_2^{-}$ have the same bond order
4. $H{e}_2^{+}$ has the same energy as two isolated $He$ atoms