review 1(3)

Question 1

State why poly(ethene) is described as an addition polymer, not a condensation polymer.

Answer 1

the polymer is the only product (of the reaction)

Question 2

Explain, in terms of its structure and bonding, why sodium fluoride has a high melting point.
ionic

Answer 2

M1 has giant (ionic structure)/giant (ionic lattice) M2 strong (electrostatic) forces/strong attraction M3 between (oppositely charged) ions
M4 large amount of (thermal/heat) energy required to overcome the forces/attraction

Question 3

State why the mass of solid in each test tube decreases

Answer 3

gas is given off

Question 4

Suggest why the mass of solid stops decreasing after four minutes

Answer 4

the reaction has finished

Question 5

Explain why the magnesium chloride has to be melted before it can be electrolysed.

Answer 5

1 ions cannot flow/move when solid
M2 ions can flow/move when liquid/molten

Question 6

Suggest why steel is not used for the positive electrode

Answer 6

(it/steel) reacts with chlorine