Paper 1 Preparation

The first ionisation energy of potassium, K, is 418 kJ mol–1.

The first ionisation energy of strontium, Sr, is 548 kJ mol–1.

Which statement helps to explain why Sr has a greater first ionisation energy than K?

• The charge on a Sr nucleus is greater than the charge on a K nucleus.

• The outer electron in a Sr atom experiences greater shielding than the outer electron in a K

  atom.

• The outer electron in a Sr atom experiences spin-pair repulsion.

• The outer electron in a Sr atom is further from the nucleus than the outer electron in a K

  atom.

What is the electronic configuration of Mg2+?

• 1s2 2s2 2p6

• 1s2 2s2 2p6 3s2

• 1s2 2s2 2p6 3s2 3p2

• 1s2 2s2 2p6 3s2 3p6 3d2 4s2

Compound X contains the elements C, H and O only.

2.00 g of X produces 4.00 g of carbon dioxide and 1.63 g of water when completely combusted.

What is the empirical formula of X?

• CHO2

• C2H2O

• C2H4O

• CH2O2

For which molecule is the dipole moment zero?

• CH3Cl

• CH2Cl2

• CHCl3

• CCl4

Which dot-and-cross diagram is correct for Al2Cl6?

• 
• 
• 
• 

The boiling points of some hydrogen halides are shown.

Look at the table.

What is the explanation for the trend in boiling point for the hydrogen halides from HCl to HI?

• The bond energies of the hydrogen halides increase from HCl to HI.

• There is an increase in the strength of the intermolecular forces of attraction from HCl to HI.

• The intermolecular hydrogen bonds become stronger from HCl to HI.

• There is an increase in the bond polarity from HCl to HI.

• A

• B

• C

• D

• a + b

• a – b

• a + 2b

• a – 2b

Nitrogen monoxide is an atmospheric pollutant that is formed inside car engines by an endothermic reaction between nitrogen and oxygen.

N2(g) + O2(g) --> 2NO(g)

Which diagram correctly represents the energy profile for this reaction?

• 
• 
• 
• 

Number 10

• 1, 2 and 3

• 1 and 2 only

• 1 and 3 only

• 2 and 3 only