Stability of Free Radical

Q. Maximum stability will be in which of the following free radicals?

1. 
2. 
3. 
4. 

Q. Which of the following free radicals is most stable

1. Primary
2. Methyl
3. Secondary
4. Tertiary

Q. The number of species having non-pyramidal shape among the following is _____.

$\left(A\right)S{O}_3$
$\left(B\right)N{O}_3^{-}$
$\left(C\right)PC{l}_3$
$\left(D\right)C{O}_3^{2-}$

Q. Arrange the bond energy of $H_a,H_b,H_c\text{and}{H}_d$ in decreasing order.

1. $H_b>H_d>H_c>H_a$
2. $H_c>H_a>H_d>H_b$
3. $H_c>H_d>H_a>H_b$
4. $H_b>H_d>H_a>H_c$

Q.

The correct increasing order of stability of the following free radicals is

1. 

2. 

3. 

4. 

Q.

The correct order for decreasing stability of the following free radicals is

1. II>III>IV>I

2. II>IV>III>I

3. I>II>III>IV

4. III>IV>II>I

Q. Homolytic fission of the following alkanes forms free radicals
$C{H}_3-C{H}_3,C{H}_3-C{H}_2-C{H}_3,(C{H}_3{)}_{2}CH-C{H}_3,C{H}_3-C{H}_2-CH(C{H}_3{)}_2.$
The increasing order of stability of the radicals is:

1. $(C{H}_3{)}_3\stackrel{.}{C}<(C{H}_3{)}_2\stackrel{.}{C}-C{H}_{2}C{H}_3<C{H}_3-\stackrel{.}{C}H-C{H}_3<C{H}_3-\stackrel{.}{C}{H}_2$
2. $(C{H}_3{)}_2\stackrel{.}{C}-C{H}_{2}C{H}_3<C{H}_3-\stackrel{.}{C}H-C{H}_3<C{H}_3-\stackrel{.}{C}{H}_2<(C{H}_3{)}_3\stackrel{.}{C}$
3. $C{H}_3-\stackrel{.}{C}{H}_2<C{H}_3-\stackrel{.}{C}H-C{H}_3<(C{H}_3{)}_3\stackrel{.}{C}<(C{H}_3{)}_2\stackrel{.}{C}-C{H}_{2}C{H}_3$
4. $C{H}_3-\stackrel{.}{C}{H}_2<C{H}_3-\stackrel{.}{C}H-C{H}_3<(C{H}_3{)}_2\stackrel{.}{C}-C{H}_{2}C{H}_3<(C{H}_3{)}_3\stackrel{.}{C}$

Q. Choose the correct stability order of the given free radicals.

1. $I>II>III>IV$
2. $II>I>IV>III$
3. $II=I>IV>III$
4. $III>IV>II>I$

Q. The correct increasing order of stability of the free radicals among the following is:

1. $(C_6{H}_5{)}_2\stackrel{\bullet }{C}H<(C_6{H}_5{)}_3\stackrel{\bullet }{C}<(C{H}_3{)}_3\stackrel{\bullet }{C}<(C{H}_3{)}_2\stackrel{\bullet }{C}H$
2. $(C{H}_3{)}_2\stackrel{\bullet }{C}H<(C{H}_3{)}_3\stackrel{\bullet }{C}<(C_6{H}_5{)}_2\stackrel{\bullet }{C}H<(C_6{H}_5{)}_3\stackrel{\bullet }{C}$
3. $(C{H}_3{)}_3\stackrel{\bullet }{C}<(C{H}_3{)}_2\stackrel{\bullet }{C}H(C_6{H}_5{)}_2\stackrel{\bullet }{C}H<(C_6{H}_5{)}_3\stackrel{\bullet }{C}$
4. $(C_6{H}_5{)}_3\stackrel{\bullet }{C}<(C_6{H}_5{)}_2\stackrel{\bullet }{C}H<(C{H}_3{)}_3\stackrel{\bullet }{C}<(C{H}_3{)}_2\stackrel{\bullet }{C}H$

Q.

Discuss briefly giving an example in each case the role of coordination compounds in:

(i) biological system

(ii) medicinal chemistry

(iii) analytical chemistry

(iv) extraction/metallurgy of metals

Q. Which of the following order(s) is/are correct?

1. Dipole moment:
   
   
2. Stability of free radical:
   
3. Basic strength: $C{H}_3{O}^{\ominus }>\stackrel{\ominus }{O}H>R{S}^{\ominus }$
   
4. Basic and nucleophilic strength: $I^{\ominus }>B{r}^{\ominus }>C{l}^{\ominus }>F^{\ominus }$

Q. Compare the stability of given free radicals

1. A > B > C
2. C > B > A
3. B > C > A
4. A > C > B

Q. Give the decreasing order of the stabilities of the following:

1. $iii>ii>i$
2. $ii>iii>i$
3. $iii>i>ii$
4. $i>iii>ii$

Q. A secondary butyl free radical is more stable than the primary butyl free radical. It is due to the

1. $-I$ effect of the $-C{H}_3$ group
2. Hyperconjugation
3. $+R$ effect of the $-C{H}_3$ group
4. $-R$ effect of the $-C{H}_3$ group

Q. $La(OH{)}_3$ is more basic than $Lu(OH{)}_3$.

Q. What is the correct order of o/p ratio when $E^{+}$ attacks the following system?

A	$PhF$
B	$PhCl$
C	$PhBr$
D	$PhI$

1. A < B < C < D
2. A = B = C = D
3. D < C < B < A
4. D < B < A < C

Q. Which of the following free radicals is pyramidal?

1. 

2. 

3. 

4. 

Q. Maximum stability will be in which of the following free radicals?

1. 
   
   
2. 
   
3. 
4. 

Q.

What is meant by stability of a coordination compound in solution? State the factors which govern stability of complexes.

Q. Correct arrangement of the following nucleophiles in the order of their nucleophilic strength is

1. $C_6{H}_5{O}^{-}<C{H}_3{O}^{-}<C{H}_{3}CO{O}^{-}$
2. $C{H}_3{O}^{-}<C{H}_{3}CO{O}^{-}<C_6{H}_5{O}^{-}$
3. $C_6{H}_5{O}^{-}<C{H}_{3}CO{O}^{-}<C{H}_3{O}^{-}$
4. $C{H}_{3}CO{O}^{-}<C_6{H}_5{O}^{-}<C{H}_3{O}^{-}$

Q. Which of the following compound give racemic mixture on nucleophilic substitution?

1. (a)
2. (a), (b), (c)
3. (b), (c)
4. (a)(c)

Q. Give the decreasing order of the stabilities of the following:

1. $iii>ii>i$
2. $ii>iii>i$
3. $iii>i>ii$
4. $i>iii>ii$

Q. Explain why $N{H}_3$ is basic while $Bi{H}_3$ is only feebly basic.

Q. Which of the following order(s) is/are correct?

1. Dipole moment:
   
   
2. Stability of free radical:
   
3. Basic strength: $C{H}_3{O}^{\ominus }>\stackrel{\ominus }{O}H>R{S}^{\ominus }$
   
4. Basic and nucleophilic strength: $I^{\ominus }>B{r}^{\ominus }>C{l}^{\ominus }>F^{\ominus }$

Q. Homolytic fission of the following alkanes forms free radicals
$C{H}_3-C{H}_3,C{H}_3-C{H}_2-C{H}_3,(C{H}_3{)}_{2}CH-C{H}_3,C{H}_3-C{H}_2-CH(C{H}_3{)}_2.$
The increasing order of stability of the radicals is:

1. $(C{H}_3{)}_3\stackrel{.}{C}<(C{H}_3{)}_2\stackrel{.}{C}-C{H}_{2}C{H}_3<C{H}_3-\stackrel{.}{C}H-C{H}_3<C{H}_3-\stackrel{.}{C}{H}_2$
2. $(C{H}_3{)}_2\stackrel{.}{C}-C{H}_{2}C{H}_3<C{H}_3-\stackrel{.}{C}H-C{H}_3<C{H}_3-\stackrel{.}{C}{H}_2<(C{H}_3{)}_3\stackrel{.}{C}$
3. $C{H}_3-\stackrel{.}{C}{H}_2<C{H}_3-\stackrel{.}{C}H-C{H}_3<(C{H}_3{)}_2\stackrel{.}{C}-C{H}_{2}C{H}_3<(C{H}_3{)}_3\stackrel{.}{C}$
4. $C{H}_3-\stackrel{.}{C}{H}_2<C{H}_3-\stackrel{.}{C}H-C{H}_3<(C{H}_3{)}_3\stackrel{.}{C}<(C{H}_3{)}_2\stackrel{.}{C}-C{H}_{2}C{H}_3$

Q. Consider the following compounds ?
Order of basicity of these compounds in decreasing order is

1. 4 > 1 > 2 >3
2. 1 > 3 > 4 > 2
3. 2 > 3 > 4 > 1
4. 1 > 3 > 2 > 4

Q. Maximum stability will be in which of the following free radicals?

1. 
2. 
3. 
4. 

Q. The most stable and basic hydride of 15th group is___________.

1. $P{H}_3$
2. $As{H}_3$
3. $Bi{H}_3$
4. $N{H}_3$

Q.

The correct order for decreasing stability of the following free radicals is

1. II>IV>III>I

2. I>II>III>IV

3. III>IV>II>I

4. II>III>IV>I

Q. The decreasing nucleophilic order of the following compounds is:
$i.\stackrel{\ominus }{{CH}_3}$ $ii.\stackrel{\ominus }{N}{H}_2$ $iii.\stackrel{\ominus }{O}H$ $iv.F^{\ominus }$

1. $\left(i\right)>\left(ii\right)>\left(iii\right)>\left(iv\right)$
2. $\left(iv\right)>\left(iii\right)>\left(ii\right)>\left(i\right)$
3. $\left(ii\right)>\left(i\right)>\left(iii\right)>\left(iv\right)$
4. $\left(ii\right)>\left(i\right)>\left(iv\right)>\left(iii\right)$