Physical Science 20
Specific Heat Capacity
The amount of heat energy required to change the temperature of a substance.
ΔQ = mcΔT
where:
 ΔQ = change in the QUANTITY of heat (joules)
 m = mass (kg)
 c = specific heat capacity (J/kg °C)
 ΔT = change in temperature (°C or K)
Mixtures
The Law of Conservation of energy states that "in any transfer
or transformation of energy, the total amount of energy
remains constant".
When two substances at different temperatures are mixed
together, the warmer substance loses heat to the cooler
substance.
ΔQ1 + ΔQ2 = 0
m1c1ΔT1 + m2c2ΔT2 = 0
Some Common Specific Heat Capacities
Substance
c (J/kg°C)
Air
Alcohol (ethyl)
Alcohol (methyl)
Aluminum
Brass
Copper
Glass (crown)
Glass (pyrex)
Glycerine
Gold
Iron
Lead
Mercury
Nitrogen (liquid)
Sand
Silver
Ice
Water
Steam
1.0 x 103
2.3 x 102
2.5 x 102
9.0 x 102
3.8 x 102
3.9 x 102
6.7 x 102
7.8 x 102
2.4 x 102
1.3 x 102
4.5 x 102
1.3 x 102
1.4 x 102
1.1 x 102
8.0 x 102
2.3 x 102
2.1 x 103
4.2 x 103
2.0 x 103
Physical Science 20
Specific Heat Capacity and Mixtures Assignment
Specific Heat Capacity
1. How much energy is lost when 54 g of iron is cooled from 90 °C to 10 °C?
2. A 300 g piece of aluminum is heated from 30 °C to 150 °C. What amount of heat energy
is absorbed?
3. Determine the temperature change in each of the following:
a. 10.0 kg of water loses 232 kJ of heat energy.
b. 500 g of copper gains 1.96 kJ of heat energy.
c. 4.80 kg of methanol gains 12.6 kJ.
4. When 2.1 x 103 J of heat energy are added to 100 g of a substance, its temperature
increases from 15 °C to 40 °C. What is the specific heat capacity of the substance?
5. A 6.0 g pellet of lead at 30 °C gains 36.8 J of heat. What will be its final temperature?
Mixtures
1. When 100 g of a metal at 94 °C is placed in 100 g of water at 10 °C, the final
temperature of the water is 17 °C. Calculate the specific heat capacity of the metal.
2. A 13.5 g spoon at 20 °C is completely submerged in a Styrofoam cup containing 200 g of
hot water at 90 °C. If the temperature of the water is lowered 1.0 °C, what is the
specific heat capacity of the spoon?
3. A 125 g Pyrex glass mug at 20 °C is filled with 200 g of coffee (assume water) at 90 °C.
What will the final temperature of the coffee and mug be if none of the heat is
transferred to the surrounding air?
Answers:
3
4
Specific Heat Capacity: (1) 1.9 x 10 J is lost (2) 3.2x10 J (3) (a) 5.5 °C (b) 10 °C (c) 10.5 °C (4) 840 J/kg°C (5) 77.2 °C
2
Mixtures: (1) 3.8 x 10 J/kg°C (2) 902 J/kg°C (3) 82 °C