Incomplete Octet

Q.

Define the octet rule and write its significance and limitations.

Q.

Why does $BeC{l}_2$ violate the octet rule?

Q.

A molecule having an incomplete octet in the central atom is

1. ${\mathrm{H}}_2\mathrm{O}$

2. ${\mathrm{NH}}_3$

3. ${\mathrm{PCl}}_5$

4. ${\mathrm{BCl}}_3$

Q.

Assertion: ${\mathrm{PF}}_5,{\mathrm{SF}}_6$ and ${\mathrm{H}}_2{\mathrm{SO}}_4$ are examples of expanded octet molecules.

Reason: Octet rule is not applicable to the second-period elements of the periodic table.

1. Both Assertion and Reason are false.

2. Assertion is true, but Reason is false.

3. Both Assertion and Reason are true. The reason is the correct explanation of Assertion.

4. Both Assertion and Reason are true. The reason is not the correct explanation of Assertion.

Q.

Draw orbit structure diagram of calcium oxide $\left(\mathrm{CaO}\right)$?

Q. Find the number of bonded and non bonded electrons in water molecule.

1. $2,4$
2. $4,6$
3. $4,4$
4. $6,4$

Q. Octet rule is not valid for which of the following molecules?

1. $C{O}_2$
2. $B{H}_3$
3. $N_2$
4. $O_2$

Q. Which of the following is not hypovalent but complete its octet?

1. $AlC{l}_3$
2. $AlB{r}_3$
3. $Al{F}_3$
4. $B{F}_3$

Q. The electron deficient compound that has 3c - 2e bond among the following:

1. $B_2{H}_6$
2. $A{l}_{2}C{l}_6$
3. $BeC{l}_2$ polymer
4. All of the above

Q. The magantate and permanganate ions are tetrahedral, due to :

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1. The $\pi$-bonding involves overlap of d-orbitals of oxygen with d-orbitals of maganese
2. There is no $\pi$-bonding
3. The $\pi$-bonding involves overlap of p-orbitals of oxygen with d-orbitals of manganese
4. The $\pi$-bonding involves overlap of p-orbitals of oxygen with p-orbitals of maganese

Q. The necessary steps required to shown the formation of $CCl$${}_4$ by Lewis electron dot diagram have been jumbled. Arrange them in a sequence :
(a) This is how an electron pair is shared between $C$ and $Cl$. This is the Lewis electron dot diagram for $CC{l}_4$.
(b) Write the symbol of chlorine and represent its valence electrons with the help of crosses.
(c) Write the symbol of carbon and represent its valence electrons with the help of dots.
(d) When carbon combines with four chlorine atoms, the carbon atom contributes four electrons for sharing whereas each chlorine atom contributes only one electron for sharing. Thus, both the atoms in $CCl$${}_4$ attain an octet.

1. $bacd$
2. $acbd$
3. $cbda$
4. $dcba$

Q. $LiCl$ and $BC{l}_3$ are examples of .

1. Duplets
2. Incomplete Octet
3. Half-filled Octet