A test chamber circulates a substance through narrow pipes. The substance must stay liquid while the chamber operates at any temperature from $∘C-35\,^\circ\mathrm{C}$ to $∘C75\,^\circ\mathrm{C}$ .

The table gives data for three possible substances at normal atmospheric pressure.

Substance	Melting point ( $∘C^\circ\mathrm{C}$ )	Boiling point ( $∘C^\circ\mathrm{C}$ )
Q	-48	88
R	-20	110
S	-95	56

Explain which substance should be used in the test chamber.

Use data from the table to explain why each of the other substances is not suitable.

Substance S is put into the chamber by mistake. The chamber is then warmed from $∘C50\,^\circ\mathrm{C}$ to $∘C75\,^\circ\mathrm{C}$ .

Explain what happens to the particles of S.

The table gives data for three possible substances at normal atmospheric pressure.

Substance	Melting point ( $∘C^\circ\mathrm{C}$ )	Boiling point ( $∘C^\circ\mathrm{C}$ )
Q	-48	88
R	-20	110
S	-95	56

Explain which substance should be used in the test chamber.

Use data from the table to explain why each of the other substances is not suitable.

Substance S is put into the chamber by mistake. The chamber is then warmed from $∘C50\,^\circ\mathrm{C}$ to $∘C75\,^\circ\mathrm{C}$ .

Explain what happens to the particles of S.

1.1 The particle model

Question 18

Markscheme

1.1 The particle model

Question 18

Markscheme

1.1 The particle model

Question 18

1.1 The particle model Questions

1.1 The particle model

Question 18

1.1 The particle model Questions