P6.4/P6.5/P6.6 - Latent heat + temperature

Question 1

internal heat

Answer 1

energy stored by particles of a substance

Question 2

sum of internal heat

Answer 2

-KE from individual motions
-potential energy from position of all particles

Question 3

What increases internal energy

Answer 3

-increasing temp of substance

Question 4

Particle composition in a solid

Answer 4

-strong forces of attraction
-fixed position
-when heated, bonds are overcome + particles may break away from structure

Question 5

Particle composition in a liquid

Answer 5

-forces of attraction aren’t strong enough to prevent random movement

Question 6

Particle composition in a gas

Answer 6

-forces of attraction are insignificant = so weak
-high speed random movement
-when heated, pressure of gas increases = more collisions

Question 7

Pressure of gas on container is caused by

Answer 7

force of impacts of gas particles against surface (collisions)

Question 8

When a substance is heated

Answer 8

-temp rises = more KE
-if it melts/boils = more potential energy of particles

Question 9

Latent heat of fusion

Answer 9

-energy needed by particles to break free from each other

Question 10

When is latent heat transferred to surroundings

Answer 10

-when a substance cools/solidifies at its melting point

Question 11

specific latent heat of fusion

Answer 11

-energy used to change the state
-of 1kg of a substance
-from a solid to a liquid
-at its metling point

Question 12

Formula for specific latent heat of fusion

Answer 12

E/m

Question 13

unit for specific latent heat of fusion

Answer 13

j/kg

Question 14

Latent heat of vapourisation

Answer 14

-energy supplied to go from liquid to gas
-allows particles to break free from one another

Question 15

Lv

Answer 15

-energy used to change 1kg of substance
-from liquid to gas
-at its boiling point

Question 16

When a gas is cooled

Answer 16

-it will condense at boiling point
-latent heat will be transferred to surroundings
-as substance forms new bonds

Question 17

Formula for Lv

Answer 17

Lv = e/m

Question 18

gas pressure cause

Answer 18

-random movement/collisions of molecules on surface

Question 19

When the temp of a gas container increases

Answer 19

-pressure increases
-molecules move faster
-total force of impacts increase

Question 20

Unpredictable motion of smoke particles is

Answer 20

-proof of the random movement of gas particles
-they push against the larger smoke particle in random directions

Question 21

volume decreases..

Answer 21

pressure increases
-less space
-so particles travel a shorter distance

Question 22

temp of gas increases if

Answer 22

compressed rapidly
-energy transferred is not enough energy transferred to surroundings

Question 23

Boyle’s law

Answer 23

pressure x volume = constant