Physical Properties of Carbon Family

Q.

Which of the alkali metal is having least melting point?

(a) Na (b) K (c) Rb (d) Cs

Q.

Which one of the following has the lowest boiling point?

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

2. ${\mathrm{H}}_2\mathrm{Te}$

3. ${\mathrm{H}}_2\mathrm{Se}$

4. ${\mathrm{H}}_2\mathrm{S}$

Q.

Explain the factors affecting the melting point.

Q.

Why does the boiling point of Group-1 metals decrease?

Q. Select correct statement about $C{O}_2,Si{O}_2,Sn{O}_2,Pb{O}_2:$

1. $C{O}_2,Si{O}_2$ are acidic
2. $Sn{O}_2$ is amphoteric
3. All of the above.
4. $Pb{O}_2$ is amphoteric

Q. The pure crystalline substance on being heated gradually, first forms a turbid liquid at constant temperature and at higher temperature turbidity completely disappears. The behaviour is a characteristic of substance forming

1. Allotropic crystals
2. Liquid crystals
3. Isomeric crystals
4. Isomorphous crystals

Q. On going down the group there is a considerable increase in covalent radius from C to Si, followed by a small increase from Si to Pb. This is due to

1. Greater shielding effect of f-orbitals
2. Greater shielding affect of d-orbitals
3. Presence of fully filled d and f- orbitals
4. Both (a) and (b)

Q.

Compare the stability of +2 oxidation state for the elements of the first transition series.

Q. Which of the following can be easily hydrolysed by water?

1. $SiC{l}_4$
2. $CC{l}_4$
3. Both (a) and (b)
4. None of the above

Q.

Which of the following has zero electron affinity?

1. Neon

2. Oxygen

3. Nitrogen

4. Fluorine

Q. On doping Ge metal with a little of In, one gets:

1. p-type semiconductor
2. n-type semiconductor
3. insulator
4. rectifier

Q. Choose the correct statement(s):
1. Carbon has unique ability to form pπ−pπ multiple bonds with itself .
2. Pb, Sn donot form pπ−pπ multiple bonds.
3. Pb, Sn form pπ−pπ multiple bonds.
4. Carbon can accomodate more than 4 electron.

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

Q. Label the diagram correctly.

1. 1-Semiconductor, 2-Non metal, 3-Metal
2. 1-Non metal, 2-Semiconductor, 3-Metal
3. 1-Metal, 2-Semiconductor, 3-Non metal
4. 1-Metal, 2-Non metal, 3-Semiconductor

Q.

Which of the following will have highest melting point?

1. C

2. Ge

3. B

4. Al

Q. In the case of alkali metals, the ionic character decreases in the order:

1. $MI>MBr>MCl>MF$
2. $MCl>MI>MBr>MF$
3. $MF>MCl>MBr>MI$
4. $MF>MCl>MI>MBr$

Q.

What is the difference between sigma and sigma star, and pi and pi star

Q.

What is the difference between binding energy and ionization energy?

Q. The correct order of melting point of group 14 elements is :

1. $C>Si>Ge>Sn<Pb$
2. $C<Si<Ge<Sn>Pb$
3. $C>Si>Ge>Sn>Pb$
4. $C<Si<Ge<Sn<Pb$

Q. What is the colour of the compound $CoC{l}_3.5N{H}_3$?

1. Yellow
2. Purple
3. Green
4. Violet

Q.

If in NH3 formation N uses its pure atomic orbitals then wrong statement is

At least three bond angles are 90

Three sigma bonds with identical strength

Lone pair will be in 2s orbital

Molecule will be in T shape

Q. The stability of hydrides of the carbon family is in the order:

1. $C{H}_4>Si{H}_4>Ge{H}_4>Sn{H}_4>Pb{H}_4$
2. $C{H}_4<Si{H}_4<Ge{H}_4<Sn{H}_4<Pb{H}_4$
3. $C{H}_4>Sn{H}_4>Ge{H}_4>Si{H}_4>Pb{H}_4$
4. None of these

Q.

Classify the following as being either a p-type or an n-type semiconductor:

$\mathrm{B}$ doped with $\mathrm{Si}$

Q. Which statement is correct among the following: (Considering the hypothetical values)

1. Radius of $Cl$ atom is $0.99\stackrel{o}{A}$ while that of $C{l}^{+}$ is $1.54\stackrel{o}{A}$
2. Radius of $Cl$ atom is $0.99\stackrel{o}{A}$ while that of $Na$ is $1.54\stackrel{o}{A}$
3. Radius of $Cl$ atom is $0.99\stackrel{o}{A}$ while that of $C{l}^{-}$ is $0.81\stackrel{o}{A}$
4. Radius of $Na$ atom is $0.95\stackrel{o}{A}$ while that of $N{a}^{+}$ is $1.54\stackrel{o}{A}$

Q. Two electrolytic cells, one containing acidified ferrous sulphate and other containing acidified ferric sulphate are connected in series. The ratioof iron deposited at cathodes in the two cells will be respectively (A) 2:1 (B) 2:3 (C) 1:1 (D) 3:2

Q. Choose the correct statement(s):
1. Carbon has unique ability to form pπ−pπ multiple bonds with itself .
2. Pb, Sn donot form pπ−pπ multiple bonds.
3. Carbon can accomodate more than 4 electron.

1. only 1 and 2
2. Only 2 and 3
3. only 1 and 3
4. 1, 2, 3

Q.

Select the correct order of electronegativity:

1. F > Cl > Br > I

2. N > P > As

3. Both (A) and (B)

4. S > O > Se

Q. In which of the following compound(s), the colour is due to charge transfer spectra?

1. $KMn{O}_4$
2. $Cr{O}_3$
3. $C{u}_{2}O$
4. All of the above

Q. Which of the following sequence will show an increase in ionisation enthalpy?

1. From $C$ to $Si$
2. From $Si$ to $Ge$
3. From $Ge$ to $Sn$
4. From $Sn$ to $Pb$

Q. Which element does not show allotropy?

1. Pb
2. Si
3. C
4. Sn

Q. Discuss the trends in chemical reactivity of group $15$ elements.