Show:
DEFINITIONS
SPECIFIC HEAT AND CALORIMETRY
GAS LAWS
THERMAL EXPANSION
RATE OF HEAT TRANSFER THROUGH CONDUCTION
100
What is the difference between heat and temperature? 
Heat is the sum of the kinetic energy of all of the particles, while temperature is the average kinetic energy. 
100

What is the specific heat capacity of water? (Don't forget units) 

4200 J kg-1 K-1

100
Describe the relationships which allow for the combined gas equation to be created. 

Boyle's Law: P is inversely proportional to V 

Charles' Law: V is directly proportional to T

Amonton's Law: P is directly proportional to T 

P1V1/T1 = P2V2/T2

100
Explain how/when most solids will expand and contract. 
With few exceptions, solids will expand when they are heated, and contract when they are cooled. 
100
If the thermal conductivity increases, what does that imply about the substance?
The higher the thermal conductivity of the substance, the better the substance is at conducting heat. Therefore the heat with transfer quicker through a substance which has a higher thermal conductivity
200
Define Thermal Equilibrium and give a real life example. 
 Thermal equilibrium is the state at which there in no more heat transfer between two objects (ie. Both objects are now at the same temperature). 


eg. If you place a spoon into a cup of coffee, the spoon with heat up and the coffee with cool down until everything is at the same temperature. 

200

How much heat is required to bring a saucepan containing 500mL of water at 20oC to boiling point? (Assume that the water remains in its liquid form at all times). 

1.68x105 J

200

A cylinder contains 0.50m3 of helium gas at 2.0atm. What volume of gas is able to escape if it is released into the atmosphere? 

V2=1m3

200
What is the coefficient of linear expansion for Brass? 

19x10-6 oC-1

200
What is the thermal conductivity of fibreglass wool?

z=0.04 W m-1K-1

300
Why is 0K referred to as absolute zero? 

At 0K (-273.15 oC), particles have stopped moving, therefore their kinetic energy is 0J. As the particles are no longer moving, particles are also no longer colliding which means that there is also zero pressure. 

300

If 100g of alcohol at 50oC is mixed with 250g of water at 20oC, what is the final temperature of the mixture? 

Tf=25.5oC

300

What volume will 2 moles of gas occupy at a pressure of 8.2x104Pa and a temperature of 290K? 

V=0.059m3

300

An electrical company strung an aluminium wire between two poles 200m apart on a day when the temperature was 25oC. They strung the wire tight to that it would not sag. Find the length of the wire when the temperature fell to -25oC on a cold winter's night. What may happen to the wire and what should be done to prevent it? 

As the temperature is decreasing, the wire is going to contract 0.238m. With this amount of contraction, the wire is likely to snap. To avoid the wire breaking, the electrical company should have left some slack to allow for the wire to expand and contract as the temperature fluctuates. 
300
What are the three relationships used to create the equation for the rate of heat flow through an object? 

R is inversely proportional the the thickness of the object (d)

R is directly proportional to the change in temperature. (T2-T1)

R is directly proportional to the area of contact (A) 

400

Avogadro's Constant (6.02x1023) represents...

Avogadro's Constant represents the the number of particles/molecules present within 1 mol of gas. 
400
How much energy is required to change a 2kg block of lead to liquid at its melting point? 

Q=4.6x104 J

400

A 1m3 flask contains gas at a temperature of 30oC and a pressure of 2.0x103Pa. Find the number of particles in the flask. 

4.78x1023 particles. 

400

A 100m long iron water pipe was laid in the ground on a hot summer's day when the temperature was 25oC. By what length would it have contracted if if the ground temperature fell to -15oC?

0.048m or 4.8cm or 48mm
400

Calculate the initial rate which heat flows through a copper-based saucepan that has a 15cm diameter, 1cm thick base. The temperature of the water in the saucepan is initially 18oC while the stove hotplate is 120oC.

R = 7.2x104 W

500
Why does the heat required increase but the temperature remain the same during a phase change? 
During a phase change the temperature does not change as the kinetic energy of the particles remains constant; however, during this time the particles are gaining potential energy which resulting in an increase in heat. 
500

An ice tray containing 200g of water at 25oC is placed in the freezer. How much heat energy has to be removed to change the water into ice at -4oC?

Q=8.94x104 J

500

If we have a cylinder of volume 4.4m3 containing 5.0x1023 particles at a pressure of 3atm. What will be the average kinetic energy of the centre of mass motion of the particles? 

Ek=4.013x10-17J

500

The space between 10m steel railway lines is 8mm at 5oC. What would be the space at 30oC?

Remember the temperature in increasing, therefore the steel is expanding and the gap is getting smaller. 

The change in length is 2.5mm. Therefore the gaps are now 5.5mm wide. 

500

Calculate the heat lost from a seal in 30 minutes. Assume the seal's total surface area is 1.1m2 and the thickness of the fat is 2.0cm. The atmosphere temperature is -25oC and the seal's body temperature is 37oC. 

1.3 x 105 J