10 minutes maximum! Can you do it in 5?

 1. Steam has a high internal energy and can cause severe burns. Internal energy is defined as...

  • A. the total intermolecular potential and random kinetic energy of the molecules of a substance.
  • B. the total intermolecular potential energy only.
  • C. the total kinetic energy only.
  • D. the total kinetic, potential and chemical energy stored in a substance.

2. 1 kg of sea water at 20 0C has a specific heat capacity of cw. What is the specific heat capacity of 2 kg of sea water at 40 0C?

  • A. ½cw
  • B. cw
  • C. 2cw
  • D. 4cw

3-5. The graph shown below shows the temperature change of solid lead as heat energy is supplied, and the lead melts. Heat energy is transferred at a constant rate.

phase change graph

  

3. Which feature of the graph above shows the specific heat capacity of solid lead?

  • A. The gradient of line z.
  • B. The gradient of line x.
  • C. The length of line y.
  • D. The area under line y.

4. Which feature of the graph above shows the specific heat capacity of liquid lead?

  • A. The gradient of line z.
  • B. The gradient of line x.
  • C. The length of line y.
  • D. The area under line y.

5. Which feature of the graph above shows the latent heat of fusion of lead?

  • A. The gradient of line z.
  • B. The gradient of line x.
  • C. The length of line y.
  • D. The area under line y.

6. The temperature of 2 substances, P and Q, are stated as 200 0C and -100 0C. In units of kelvin (K), this is....

  • A. P = 73 K, Q = -373 K
  • B. P = 173 K, Q = 473 K
  • C. P = 473 K, Q = 373 K
  • D. P = 473 K, Q = 173 K
7. Approximately 4000 J of energy is needed to heat 1 kg of copper by 10 0C. How much energy is needed to heat 0.5 kg of copper by 40 0C?

By Wdwd | CC BY-SA 3.0
  • A. 16 kJ
  • B. 2 kJ
  • C. 1 kJ
  • D. 8 kJ

 

 

8-10. A sample of 1 kg of liquid is heated by a 100 W electric heater. The graph shows the increase in temperature with time:

heating graph, temperature against time

 

  

8. What is total heat energy Q suppiled to the liquid in this time?

  • A. 10 000 J
  • B. 20 000 J
  • C. 1 000 J
  • D. 2 000 J

9. Which of the following formulas can be used to calculate the specific heat capacity c of the liquid?

     

10. The experiment is repeated, once with double the mass of the same liquid, and a second time with a liquid of lower specific heat capacity. What effect would this have on the gradient of the graph above?

 Higher mass of liquid Liquid of lower specific heat capacity
A
 gradient of line decreases gradient of line decreases
B
 gradient of line decreases gradient of line increases
C
 gradient of line increases gradient of line decreases
D
 gradient of line increases gradient of line increases