Name ………………………………..

Specific Heat capacity

Compound A is an imaginary solid. It has a Specific Heat Capacity of 1000 J / kg °C

Section 1

a / A 1 kg block of Compound A is heated, increasing its temperature by 1 °C.
How much energy has been added to the block?
b / A 1 kg block of Compound A is heated, increasing its temperature by 10 °C.
How much energy has been added to the block?
c / A 1 kg block of Compound A is heated, increasing its energy by 1000 Joules.
How much warmer does it get?
d / A 1 kg block of Compound A is heated, increasing its energy by 3000 Joules.
How much warmer does it get?
e / A 1 kg block of Compound A is cooled, reducing its energy by 1000 Joules.
What is the temperature change?
f / A 1 kg block of Compound A is at 20°C.
How much energy is needed to get it to be 30°C?
g / A 10 kg block of Compound A is at 25°C.
How much energy is needed to get it to be 35°C?
h / A 10 kg block of Compound A is at 25°C.
How much energy is removed to get it to be 24°C?
i / A 5 kg block of Compound A is at 20°C.
How much energy is needed to get it to be 24°C?

Section 2

Specific Heat Capacity values
Water / 4,180 J / kg °C
Copper / 390 J / kg °C
Glass / 840 J / kg °C
a / Which substance requires the least amount of energy to raise its temperature?
b / How much energy is needed to increase the temperature of 1kg of water by 10°C?
c / How much energy is needed to increase the temperature of 1kg of copper by 10°C?
d / A 1 kg block of copper is put in 2 kg of water.
How much energy is needed to increase the temperature by 10°C?
e / A 2 kg block of copper is put in 1 kg of water.
How much energy is needed to increase the temperature by 10°C?
f / A 1 kg block of copper is put in 1 kg of water, inside a glass jar of 1kg.
How much energy is needed to increase the temperature by 10°C?
g / A 1 kg block of copper is put in 1 kg of water, inside a glass jar of 0.5kg.
How much energy is needed to increase the temperature by 10°C?
h / A 1 kg block of copper is put in 1 kg of water, inside a copper beaker of 1kg.
How much energy is needed to increase the temperature by 10°C?
i / 3 kg of water is in a 2kg copper beaker.
How much energy is needed to increase the temperature by 5°C?

Section 3 (Round any numbers to one decimal place)

a / 10,000 J is added to 1kg of water.
How much does the water temperature increase by? / 2.4 °C
b / 10,000 J is added to 1kg of copper.
How much does the water temperature increase by? / 25.6 °C
c / 10,000 J is added to 1kg of glass.
How much does the water temperature increase by? / 11.9 °C
d / 20,000 J is added to 4kg of copper.
How much does the water temperature increase by? / 12.8 °C
e / 5,000 J is added to 5 kg of water.
How much does the water temperature increase by? / 0.2 °C
f / 20,000 J is added to 1kg of water in a copper beaker of 1kg.
How much does the temperature increase by? / 4.4 °C
g / 20,000 J is added to 2kg of water in a copper beaker of 1kg.
How much does the temperature increase by? / 2.3 °C
h / 15,000 J is to be added to 2kg of water in a copper beaker of 1kg at 20.0 °C.
What will the new temperature be? / 21.7 °C
i / 2kg of water at 30 °C is poured into a 1kg copper beaker at 20 °C.
What will the temperature of the water and copper beaker be together? / 29.6 °C

Section 4

I want to measure the Specific Heat Capacity of a new substance Compound B

What practical problems are there in measuring its Specific Heat Capacity?

Knowing how much energy has been added to the substance – how much energy has been applied and also how much energy has been lost.
To keep energy loss to a minimum, insulation needs to be applied to the container.
The container in which the substance is held is also likely to absorb energy and increase in temperature. The Specific Heat Capacity of the container would therefore also need to be known. The temperature of the container would need to be known before and after any energy is applied – this is best ensured by allowing enough time for both Compound B and the container to reach the same temperature.

Section 5

How could we make a block of material that had the same property as Compound A?

Compound A has a Specific Heat Capacity between that of Water (which is higher) and Copper and Glass (both of which are lower).
A hollow block of Copper in to which water has been poured and then sealed, would therefore have a Specific Heat Capacity somewhere between that of Water and Copper. The actual value would depend on the relative mass of the copper and water used.
Assume we have “x” kg of Water and “y” kg of copper.
To raise each by one degree C we would need: 4,180x Joules for the water and 390y Joules for the copper, or (4,180x + 390y) Joules in total.
If this was Compound A then to raise the total mass by one degree C we would need: 1,000(x + y) Joules
So (4,180x + 390y) = 1,000(x + y) in other words: y= (3,180 / 610) x
Or y = 5.21x. So for every 1kg of copper, 5.21kg of water would need to be added.