Bond Pairs and Lone Pairs

Q.

The correct order of a dipole moment is

1. ${\mathrm{CH}}_4<{\mathrm{NF}}_3<{\mathrm{NH}}_3<{\mathrm{H}}_2\mathrm{O}$

2. ${\mathrm{NH}}_3<{\mathrm{NF}}_3<{\mathrm{CH}}_4<{\mathrm{H}}_2\mathrm{O}$

3. ${\mathrm{NF}}_3<{\mathrm{CH}}_4<{\mathrm{NH}}_3<{\mathrm{H}}_2\mathrm{O}$

4. ${\mathrm{H}}_2\mathrm{O}<{\mathrm{NH}}_3<{\mathrm{NF}}_3<{\mathrm{CH}}_4$

Q. Among the boron trihalides, which is the strongest Lewis acid?

1. $B{F}_3$
2. $BC{l}_3$
3. $BB{r}_3$
4. All have the same acidic character

Q.

How many neutrons are present in C-14 atom of carbon?

Q. Explain the structure of an atom using a diagram.

Q. Assertion (A) : $B{F}_3$ is a weaker Lewis acid than $BC{l}_3$.
Reason (R) : $B{F}_3$ is is less electron-deficient than $BC{l}_3$.

1. (A) is correct; (R) is incorrect.
2. (A) is incorrect; (R) is correct.
3. (A) is correct; (R) is correct and (R) correctly explains (A).
4. (A) is correct; (R) is correct and (R) doesn't explain (A) correctly.

Q. Bond order of $N-O$ bonds in nitrate ion is:

1. $1.33$
2. $1.25$
3. $1.50$
4. $1$

Q. Dative bonds is not present in

1. (CH₃)₃NO

2. Al₂Cl₆

3. N₂H₄

4. NH₄⁺

Q. Calculate the sum of lone pairs of electrons in the central atoms of the molecules $XeO{F}_4,[Xe{O}_6{]}^{4-}$ and $Cl{F}_3$.

Q.

Is a 100% co-valent compound possible?

Q. Number of lone pairs of electrons in the central atom of $SC{l}_2,O_3,Cl{F}_3$ and $S{F}_6$, respectively, are :

Q. Which of the following does not contain any coordinate bond?

1. $H{F}_2^{-}$
2. $H_3{O}^{+}$
3. $B{F}_4^{-}$
4. $N{H}_4^{+}$

Q.

An ion ${\mathrm{X}}^{-}$ contains 18 electrons and 18 neutrons. What is the atomic number of the element X?

Q.

Ionization energy of nitrogen is greater than oxygen due to

1. increased attraction of electron towards the nucleus

2. extra stability of half filled ‘p’ orbital

3. small size of ${\mathrm{N}}_2$

4. none of these

Q.

The number of electron pairs in $OS{F}_4$ is

1. 4

2. 5

3. 5.5

4. 6

Q.

What is the charge present on the hydrogen when a hydrogen bond is formed?

Q. The coordinate bond in $B{F}_4^{-}$ can be considered a sigma bonnd.

Q. Which of the following metal ions will have maximum number of unpaired electrons?

1. 
2. 
3. 
4. 

Q.

The total number of lone-pairs of electrons in melamine is _____

1. 2

2. 4

3. 6

4. 8

Q. How many hydrogen bonded water molecule (S) are associated in $CuS{O}_{4}5H_{2}O$

Q.

A metal ion combines with a negative radical containing a chlorine atom. If the number of oxygen atoms in one molecule of the salt is 8, find the valency of the metal and identify the negative radical(s)

Q. The sum of the number of lone pairs of electrons present on each central atom in the following species is
$[TeB{r}_6{]}^{2-},[Br{F}_2{]}^{+},SN{F}_3$ and $[Xe{F}_3{]}^{-}$
(Atomic numbers: $N=7,F=9,S=16,Br=35,Te=52,Xe=54$)

Q. How do you calculate formal charge of a molecule?

Q. Calculate the value $x-yforXeO{F}_4.$ ($x$ = number of $\sigma$ bond pair and $y$= number of lone pair on central atom)

Q. The total number of lone pairs of electrons present in $N_2{O}_3$ is

Q. Total number of lone pair of electrons in $I_3{}^{-}$ ion is :

1. $9$
2. $12$
3. $3$
4. $6$

Q.

The shape of covalent molecule $M{X}_3$ is

1. Pyramidal

2. T - shaped

3. Triangular

4. Either of these depending on the number off lone pairs of electrons on M

Q. Assign number 1 for least to 4 for most, to indicate the relative base strength of the following (1)C6H5NH2 (2)p-NO2C6H4NH2 (3)m-NO2C6H4NH2 (4)P-CH3OC6H4NH2

Q. The ratio of lone pair and bond pair electrons on central $I$ atom in $I_3^{-}$:

1. $1$
2. $0.6$
3. $1.5$
4. $0.5$

Q. A molecule having 3 bond pairs and 2 lone pairs will have ?

1. Linear structure
2. T-shaped structure
3. Trigonal planar structure
4. Square pyramidal structure

Q.

Question 06

In NO_3^- ion, the number of bond pairs and lone pairs of electron on nitrogen atom are

(a) 2, 2

(b) 3, 1

(c) 1, 3

(d) 4, 0