Paper One

Question 1

State two observations when magnesium nitrate is heated

Answer 1

-brown fumes
-solid disappears and white ppt forms

Question 2

Explain in term of entropy why the combustion of prop2en1ol is always feasible in the gaseous state

Answer 2

DS tot always positive as both delta s surrounding and delta s system are positive

Question 3

Describe what effect if any increasing the pressure would have on the equilibrium constant Kp

Answer 3

Kp remains unchanged, equilibrium moves to the rhs to keep kp constant

Only temperature affects kp as if temperature increases kp increases

Question 4

MnO4 - colour

Answer 4

Purple

Question 5

M2+ colour

Answer 5

Pale pink

Question 6

Lithium flame colour

Answer 6

Crimson

Question 7

Barium flame colour

Answer 7

Green

Question 8

Sodium flame colour

Answer 8

Bright yellow

Question 9

Potassium flame colour

Answer 9

Lilac

Question 10

Caesium flame colour

Answer 10

Blue

Question 11

Calcium flame colour

Answer 11

Brick red

Question 12

Strontium flame colour

Answer 12

Brick red

Question 13

Explain why the data book value for the standard enthalpy change if neutralisation of the ethanoic acid with sodium hydroxide is -55.2kJ mol-1 but the value for hydrochloric acid is -57.1kJmol-1

Answer 13

Ethanoic acid is a weak acid and doesn’t completely dissociate some energy is used to fully ionise the ethanoic acid