Topic 4/14 Review

Topic 4/14 Review

Open Ended

Explain the electrical conductivity of molten Na₂O and P₄O₁₀.

«molten» Na2O has mobile ions/charged particles AND conducts electricity

«molten» P4O10 does not have mobile ions/charged particles AND does not conduct electricity/is poor conductor of electricity

Open Ended

Describe the nature of ionic bonding.

electrostatic attraction AND oppositely charged ions

Open Ended

Outline whether you expect the bonds in SO₂ to be polar, giving a brief reason.

polar AND oxygen is more electronegative than sulfur

Open Ended

State the shape and bond angle of SCl₂

bent OR V-shaped;

103 degrees (accept values from 101-109 degrees)

Open Ended

State the electron domain geometry and the molecular geometry of SCl₄

EDG: trigonal bipyramidal

MG: see-saw

Open Ended

Predict, giving a reason, which of the following structures is the most likely for the molecule phosgene, COCl₂

• structure A more likely

• all formal charge values 0

•  $FC=V-\frac{1}{2}B-N$  

Open Ended

Explain the solubility of phosgene, COCl2, in methanal, H₂CO.

soluble;

both phosgene and methanal are polar;

both have London dispersion forces and dipole-dipole interactions

Open Ended

Suggest two reasons why solid calcium has a greater density than solid potassium.

stronger metallic bonding

smaller ionic/atomic radius

 

two electrons per atom are delocalized

OR

greater ionic charge

 

greater atomic mass

Open Ended

Describe the bonding in metals.

electrostatic attraction;

between lattice of positive ions/cations AND a <<sea of >> delocalized electrons;

Multiple Choice

The hybridization of carbon in graphite is

• sp

• sp2

• sp3

• sp4

Open Ended

Explain, discussing the structure and bonding, why graphite is used as pencil lead.

graphite is stacks of 2D layers of carbon in hexagonal rings

layers are held weakly together by intermolecular forces

layers can easily break off from other and stick to paper

Open Ended

Compare, giving a reason, the melting points of SiO₂ and CO₂.

melting point of SiO2 is considerably greater <<solid at room temp, CO2 is gas at room temp>>;

SiO2 is a giant covalent structure - melting involves breaking apart strong covalent bond

CO2 is a simple molecule so melting involves breaking weak London dispersion forces

Multiple Select

Which of the following are true of the bonding in ethyne?

• there are two 2p orbitals involved in bonding

• there is one 2s orbital involved in bonding

• there are three sp hybridized orbitals

• two sp hybridized orbitals form two sigma bonds

Multiple Select

which of the following are true of pi bonds?

• overlap sideways

• overlap occurs above and below the bond axis

• one p orbitals forms 2 pi bonds