EASY
AS and A Level
IMPORTANT
Earn 100

The table lists bond lengths and bond energies of some hydrogen halides.

Hydrogen halide Bond length / nm Bond energy / kJ mol-1
HCl 0.127 431
HBr 0.141 366
HI 0.161 299

Suggest why the bond energy values decrease in the order HCl>HBr>HI.

Important Questions on Chemical Bonding

EASY
AS and A Level
IMPORTANT

The table lists bond lengths and bond energies of some hydrogen halides.

Hydrogen halide Bond length / nm Bond energy / kJ mol-1
HCl 0.127 431
HBr 0.141 366
HI 0.161 299

Suggest a value for the bond length in hydrogen fluoride, HF.

MEDIUM
AS and A Level
IMPORTANT
Predict, using VSEPR theory, the shape of tetrachloromethane, CCl4 molecule, draw dot-and-cross diagram for the covalently bonded molecule.
MEDIUM
AS and A Level
IMPORTANT
Predict, using VSEPR theory, the shape of beryllium chloride, BeCl2 molecule, draw dot-and-cross diagram for the covalently bonded molecule.
MEDIUM
AS and A Level
IMPORTANT
Predict, using VSEPR theory, the shape of phosphorus(III) chloride, draw dot-and-cross diagram for the covalently bonded molecule.
MEDIUM
AS and A Level
IMPORTANT
Draw dot-and-cross diagram for hydrogen sulphide, H2S molecule and then predict the shape.
MEDIUM
AS and A Level
IMPORTANT
Draw dot-and-cross diagram for phosphine, PH3 molecule and then predict the shape.
EASY
AS and A Level
IMPORTANT
Draw dot-and-cross diagram for a molecule of selenium hexafluoride, SeF6. A single selenium atom has six electrons in its outer shell.