Paper 1 Density

Question 1

Density (Kg/m3) = Mass (kg) / Volume (m3)

Answer 1

Density = M/V

Question 2

Find Volume of a regular shape

Answer 2

Measure length, convert into m and cube it

Question 3

Find Volume of a regular shape

Answer 3

Measure length, convert into m and cube it

IE length x width x height

Question 4

Steps of finding the mass of an irregular shape

Answer 4

1. Find the mass using a balance in kg
2. Use displacement to find the volume
3. Fill a EUREKA can with water
4. Put the object in the water
5. Water will be displaced by the object
6. The water will travel down the spout
7. Measure the volume of water in a measuring cylinder
8. Plug the figures in the formula
9. Density (Kg/m3) = Mass (kg) / Volume (m3)

Question 5

How do you find the uncertainty in density results?

Answer 5

uncertainty in density results

Highest - lowers density /2 = KG/M3

Question 6

Unit for specific latent heat

Answer 6

Joules per kg

Question 7

Density required practical

Answer 7

Density independent variable: MATERIAL being tested
Dependent variable: VOLUME & MASS
CONTROL variable: TEMPERATURE

Question 8

Solid & liquids cannot be squashed …

Answer 8

Solid & liquids cannot be incompressible (squashed)

Question 9

What is the LATENT HEAT OF FUSION

Answer 9

The energy needed for a substance to change from SOLID to LIQUID (ie melt)

Question 10

What is the LATENT HEAT OF VAPORISATION

Answer 10

The energy needed for a substance to change from LIQUID to GAS

Question 11

What is the SPECIFIC LATENT HEAT?

Answer 11

The specific latent heat is the ENERGY needed to cause 1kg of a substance to CHANGE STATE

Question 12

What is Sublimation?

Answer 12

Sublimation is when a changes changes from a SOLID to a GAS without having a LIQUID phase
(the reverse from GAS to SOLID is desublimation)

Question 13

Energy for a change of state

Answer 13

Energy for change of state =mass x specific latent heat

Joules) (kg) (J/kg

Question 14

What happens to the particle when you increase in temperature?

Answer 14

An increase in temperatures increases the speed of the particles

Question 15

If you are carrying out a density test what happens if the object is less dense than water?

Answer 15

An object less dense than water will float.

Question 16

STEAM and WATER - specific latent heat.

Answer 16

STEAM contains more ENERGY than the same mass of WATER at the same temperature

Question 17

The specific latent of heat of fusion of water is 334000J/kg.

If there was 500g of ice in the system at the start, calculate how much energy is needed to completely melt the ice once it has reach oC

Answer 17

Energy for change of state =mass x specific latent heat
(Joules) (kg) (J/kg)

= 0.500Kg x 334000J/kg
= 167000J