Specific Heat Capacity
Data
Use the following for Specific Heat capacities
|
Substance |
Specific Heat Capacity c |
Units |
|
Water |
4200 |
J kg-1 K-1 |
|
Copper |
380 |
J kg-1 K-1 |
|
Methylated Spirit |
2500 |
J kg-1 K-1 |
|
Turpentine |
1800 |
J kg-1 K-1 |
Notes
- The heat capacity of an object is the heat
required to raise the all of the object’s temperature by 1K
- When heating a liquid you have to heat the vessel
that it is in as well.
- When an object at high temperature is dropped into a
liquid at low temperature there is a net heat flow from the high
temperature object to the low temperature object until they are both at
the same temperature.
- Unless you state “Ignoring heat losses” in each
question you will lose a mark!
1 Find the
quantity of heat needed to heat 0.50 kg of copper from 20oC to 50
°C. 5700J
2 When 0.25 kg
of ice are heated from -10 °C to -2 °C the heat supplied is 4200 J. Find the
specific heat capacity of ice. 2100 Jkg-1K-1
3
A vessel of heat capacity 30 J K-1 contains 0.30 kg of water at 10
°C. When heated by a Bunsen burner for 5 min the temperature rises to 90 °C. At
what rate does the Bunsen supply heat energy? 344W
4
A piece of iron of mass 0.20 kg is heated to 100 °C and dropped into 0.15 kg of
water at 20 °C. If the temperature of the mixture is 30 °C, find a value for
the specific heat capacity of iron. 450 Jkg-1K-1
5
A piece of iron of mass 0.05 kg is heated in a flame and then quickly
transferred to a calorimeter of mass 0.05 kg and specific heat capacity 360 J
kg-1 K-1 containing 0.18 kg of water at 18 °C. If the
temperature of the water rises to 43 °C, find the temperature of the flame. The
specific heat capacity of the iron is 450 J kg-1 K-1. 903 oC
6 Which would result in the more serious burn if dropped
onto your outstretched hand a white-hot spark from a firework, or a lump of
red-hot iron? Explain your answer.
The white hot spark has a higher
temperature than the lump of iron
The lump of iron has a greater
mass than the white hot spark
They both have the same specific
heat capacity.
Lump of iron has greater store of
heat energy
The rate of heat transfer from the
white hot spark will be greater for the spark than the lump of iron.
A greater quantity of heat will be
transferred from the iron
Causing more serious skin damage.
0.20 kg of alcohol is contained in a
vessel of heat capacity 80 J K-1. When heated for 9 min by a 50 W
immersion heater the temperature rises from 15 °C to 65 °C. Find the specific
heat capacity of alcohol. 2300 Jkg-1K-1
7.
When 1 kg of brine is heated by a 500
W immersion heater for 1 min its temperature rises from 15 °C to 25 °C. Find
its specific heat capacity 3000 Jkg-1K-1
8. Find
the rise in temperature of 0.5 kg of water that is heated by, 1 kW immersion
heater for 84 s. 40K
9. A
block of lead of mass 1 kg is heated for 56 s by a heater of power 50 W. The
temperature rises from 18 °C to 38 °C. Find the specific the capacity of lead. 140 Jkg-1K-1
10. A copper
vessel of mass 0.1 kg contains 0.1 kg of turpentine. If it is heated for 109 s
by a heater of power 100 W, find the rise in temperature. 50K
11. An
immersion heater heats 0.60 kg of water in a vessel of heat capacity 120 J K-1 through 20 °C. If the
heater is used for the same time with 0.48 kg of methylated spirit in the
vessel, find the rise of temperature. 40K
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