Unit 5 - Solids , liquids and gases

Question 1

extra - discuss the linearity property of thermometers

Answer 1

(1) equal spacing between units
(2) equal change in liquid column size for equal temperature change along the whole scale
(3) change in length of liquid column same for all degrees

Question 2

extra- suggest reasons why a thermometer might not be linear

Answer 2

• non uniform capillary tube
• non linear liquid expansion property

Question 3

extra- how can you increase the range of a thermometer

(⬇sensitivity ⬆ range

Answer 3

(1) longer capillary
(2) liquids with less expansivity
(3) smaller bulb
(4) smaller bulb
(5) wider capillary tube

Question 4

extra - suggest when a thermocouple thermometer is more suitable than a liquid-in-glass thermometer.

Answer 4

rapidly varying temperature

Question 5

imp- explain in terms of forces between their molecules, why gases expand more than solids when they undergo the same rise in temperature

Answer 5

molecules of solids have stronger attraction forces between them so spaces are hardly increased but in gases forces between molecules are too weak so spaces easily become wider and they move apart easily

Question 6

describe in terms of momentum of the molecules, how a pressure is exerted on the walls of a cylinder (3)

Answer 6

molecules collide with walls
change of momentum causes force (to be exerted on walls)
pressure = force / area (so pressure is exerted on walls)