Thermometers
Heat Capacity
Latent Heat
Heat Transfer
Gas Laws
100
Why does a laboratory thermometer not have a constriction in its capillary tube?
Because it must respond immediately to temperature changes and allow the liquid to move freely up and down the tube.
100
What is meant by the heat capacity of a body?
The amount of heat energy required to raise the temperature of a body by 1°C (or 1 K).
100
What is meant by latent heat?
Heat energy absorbed or released during a change of state without a change in temperature.
100
Name the three modes of heat transfer.
Conduction, convection, and radiation.
100
State Boyle's Law.
For a fixed mass of gas at constant temperature, the pressure of the gas is inversely proportional to its volume.
200
What is the Temperature Range of a Thermocouple?
−200°C to 1800°C
200
Which of the following has the greater heat capacity: a cup of water or a swimming pool of water? Explain.
The swimming pool, because it contains more mass and therefore requires more energy to raise its temperature by 1°C.
200
What is meant by the specific latent heat of a substance?
The amount of heat energy required to change the state of 1 kg of a substance without changing its temperature.
200
Which mode of heat transfer occurs mainly in solids by the vibration and collision of particles?
Conduction.
200
State Charles' Law.
For a fixed mass of gas at constant pressure, the volume of the gas is directly proportional to its absolute temperature.
300
What special feature of a clinical thermometer allows it to retain its reading after being removed from a patient's body?
The constriction (or kink) in the capillary tube.
300
A 2 kg block absorbs 1000 J of heat and its temperature rises by 5°C. Calculate its specific heat capacity.
100 J kg−1°C−1.
300
During the melting of ice at 0°C, why does the temperature remain constant even though heat is being supplied?
The heat is used to change the state of the ice to water rather than increase its temperature.
300
Which mode of heat transfer occurs in liquids and gases through the movement of heated fluid?
Convection.
300
State the Pressure Law.
For a fixed mass of gas at constant volume, the pressure of the gas is directly proportional to its absolute temperature.
400
Why is a clinical thermometer unsuitable for measuring the temperature of hot liquids in a laboratory?
Its temperature range is small (about 35°C–42°C) and it is designed only for measuring human body temperature.
400
Two substances of equal mass absorb the same amount of heat. Substance A experiences a smaller temperature rise than Substance B. Which substance has the higher specific heat capacity?
Substance A has the higher specific heat capacity.
400
What is the difference between the specific latent heat of fusion and the specific latent heat of vaporization?
The specific latent heat of fusion is the energy required to change 1 kg of a substance from solid to liquid without a temperature change, while the specific latent heat of vaporization is the energy required to change 1 kg of a substance from liquid to gas without a temperature change.
400
Heat from the Sun travels through the vacuum of space to Earth. Which mode of heat transfer is responsible for this?
Radiation.
400
Which gas law describes the relationship between pressure and volume when temperature remains constant?
Boyle's Law.
500
A laboratory thermometer has a temperature range of -10°C to 110°C. Explain why this thermometer would be suitable for measuring the temperature of boiling water but not the temperature inside a blast furnace.
The thermometer is suitable for boiling water because its temperature range includes 100°C, the boiling point of water. It is not suitable for a blast furnace because furnace temperatures are much higher than 110°C and would exceed the thermometer's range, potentially damaging it and giving inaccurate readings.
500
A 0.5 kg sample of water (c = 4200 J kg⁻¹ °C⁻¹) is heated from 20°C to 30°C. Calculate the heat energy absorbed.
21,000 J.
500
A 2 kg block of ice at 0°C melts completely. If the specific latent heat of fusion of ice is 334,000 J kg⁻¹, calculate the energy required.
668,000 J.
500
A metal spoon is left in a cup of hot tea. After a few minutes, the handle becomes hot. Explain how heat reached the handle.
Heat was transferred by conduction through the metal from the hot end to the cooler end.
500
Why must temperature be measured in Kelvin when applying Charles' Law and the Pressure Law?
Because the laws are based on absolute temperature, and Kelvin begins at absolute zero.