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 ^{0}C has a specific heat capacity of c_{w}. What is the specific heat capacity of 2 kg of sea water at 40 ^{0}C?
 A. ½c_{w}
 B. c_{w}
 C. 2c_{w}
 D. 4c_{w}


35. 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.


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 ^{0}C and 100 ^{0}C. 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 ^{0}C. How much energy is needed to heat 0.5 kg of copper by 40 ^{0}C? 
By Wdwd  CC BYSA 3.0 
 A. 16 kJ^{}
 B. 2 kJ^{}
 C. 1 kJ^{}
 D. 8 kJ

 
810. A sample of 1 kg of liquid is heated by a 100 W electric heater. The graph shows the increase in temperature with 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 
 
