Chapter 11_Group 14

Which of the following explains why carbon has a higher melting point than tin?

• Carbon has a giant covalent structure.

• Carbon has higher ionisation energy compared to tin.

• The metallic bonds in carbon are stronger than the bonds in tin.

• The arrangement of carbon atoms in the lattice is more compact due to its smaller size.

Answer explanation

Metallic bonds in tin are weak due to its larger size.

Which of the following properties of Group 14 tetrachloride increases when going down the group?

• Stability

• Basicity

• Boiling point

• Thermal stability

Answer explanation

When going down the group, the melting point and boiling point of the tetrachloride increase due to stronger van der Waals forces.

Which of the following compounds has the following properties?

• * Liquid at room temperature and pressure

• * Produce acidic fume when added to water

• CCl₄

• PbCl₂

• PCl₅

• SnCl₄

The Group 14 compound having the highest melting point is

• CH₄

• SiCl₄

• PbCl₄

• SnCl₂

Which of the following oxides is the easiest to decompose when heated?

• GeO₂

• CO₂

• PbO₂

• SnO

Which of the following statements is true about the Group 14 tetrachlorides?

• The boiling point of the tetrachlorides increases when going down the group.

• The tetrachlorides become increasingly ionic in nature when going down the group.

• The tetrachlorides become increasingly volatile when going down the group.

• The M - Cl bond enthalpy in the tetrachlorides increases when going down the group.

Which of the following explains why SiCl₄ is hydrolysed in water but CCl₄ is not hydrolysed?

• The C - Cl bond enthalpy is lower than the Si - Cl bond enthalpy

• The carbon atom has a smaller atomic radius than the silicon atom

• The C in CCl₄ has a stable electron configuration

• The silicon atom has available 3d orbitals for dative bonding water molecules.

A second period Group 14 element forms two oxides, MO and MO₂. Which of the following is not true about the oxides?

• MO is colourless and neutral

• MO is thermally stable but not MO₂

• MO₂ is colourless and acidic

• MO is polar but MO₂ is non-polar

Why do Group 14 elements tend to form oxides and chlorides with oxidation number +2 when going down the group?

• The size of the atom increases when going down the group.

• The inert electron pair effect of the electrons in the s orbital.

• The metallic character of the elements increases when going down the group.

• The standard reduction electrode potential increases when going down the group.

The diagram shows the structure of a silicate unit.

Which of the following is the correct formula of this unit?

• SiO₃^2-

• Si₂O₅^2-

• Si₂O₇^6-

• Si₃O₄^2-

Answer explanation

Two silicate tetrahedrons

In each silicate unit, there is a silicon atom bonded to four oxygen atoms.

Two silicate tetrahedrons share one oxygen atom.