Define specific heat capacity .

Specific heat capacity is the energy required to raise the temperature of one kilogram of a substance by one kelvin.

Define specific latent heat .

Specific latent heat is the thermal energy required to change the state of one kilogram of a substance with no change in temperature.

Why does vaporising a mass of water need roughly seven times more energy than melting the same mass of ice?

Melting only needs enough energy to increase the separation between molecules so they can flow over each other. Vaporising needs enough energy to completely separate the molecules and overcome all the intermolecular forces between them, which requires much more energy.

The thermodynamic Kelvin temperature scale is an absolute scale where each degree is the same size as those on the .......... scale.

The thermodynamic Kelvin temperature scale is an absolute scale where each degree is the same size as those on the Celsius scale.

True or False? Water has a low specific heat capacity, which is why it is used in radiators to heat homes.

False. Water has a very high specific heat capacity, so it releases a large amount of energy as it cools, meaning it stays hot in a radiator for a long time.

What is the aim of Core Practical 12?

To calibrate a thermistor so that it can be used as a thermometer.

What are the independent and dependent variables in Core Practical 12?

Independent variable : temperature (°C) Dependent variable : resistance of the thermistor (Ω)

How are the fixed resistor and ohm-meter connected relative to the thermistor in Core Practical 12?

The fixed resistor is connected in series with the thermistor, and the ohm-meter is connected in parallel across the thermistor to measure its resistance.

How are temperature and resistance readings taken across the full range in Core Practical 12?

Starting with the thermistor in ice, the water is heated with a Bunsen burner and stirred gently to keep the temperature even. Temperature and resistance are recorded at approximately 5 °C intervals until the water boils.

Give two ways to reduce systematic errors in Core Practical 12.

Read the thermometer at eye level Check the zero error on the ohm-meter by connecting the leads across its terminals

In Core Practical 12, the water should be .......... gently at all times to keep the temperature as even as possible throughout the beaker.

In Core Practical 12, the water should be stirred gently at all times to keep the temperature as even as possible throughout the beaker.

True or False? In Core Practical 12, the current should be left switched on between readings to save time.

False. The current should be turned off between readings . Leaving it on would heat the wires and thermistor, introducing a random error into the resistance readings.

What is the aim of Core Practical 13?

To determine the specific latent heat of fusion of ice.

What are the independent and dependent variables in Core Practical 13?

Independent variable : energy supplied by the heater, measured with a joulemeter (J) Dependent variable : temperature, T , of the ice/water (°C)

Give two ways to improve the accuracy of Core Practical 13.

Apply lagging or insulation to the funnels and beakers to reduce energy lost to the surroundings Allow the heater to cool between readings so the rate of heating and starting temperature are the same each time

In Core Practical 13, ice must be measured into the beaker using a .......... rather than handled with bare hands.

In Core Practical 13, ice must be measured into the beaker using a spoon rather than handled with bare hands.

True or False? Repeating Core Practical 13 several times and averaging the mass of melted ice reduces systematic errors.

False. Repeating and averaging reduces random errors . Systematic errors, such as heat lost to the surroundings, must instead be reduced by insulating the apparatus.

International A Level (IAL)PhysicsEdexcelFlashcards5. Thermodynamics, Radiation, Oscillations & CosmologyThermal Energy Transfer

Thermal Energy Transfer (Edexcel International A Level (IAL) Physics): Flashcards

Exam code: YPH11

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FrontSpecific Heat Capacity & Latent Heat
Define specific heat capacity.
FrontSpecific Heat Capacity & Latent Heat
State the equation for the change in heat energy, ΔE, of a substance and define each term.
BackSpecific Heat Capacity & Latent Heat
$Δ E = m c Δ θ$
ΔE = change in heat energy (J)
m = mass (kg)
c = specific heat capacity (J kg^-1 K^-1)
Δθ = change in temperature (K or °C)

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Cards in this collection (21)

Define specific heat capacity.
Specific heat capacity is the energy required to raise the temperature of one kilogram of a substance by one kelvin.
Define specific latent heat.
Specific latent heat is the thermal energy required to change the state of one kilogram of a substance with no change in temperature.
State the equation for the change in heat energy, ΔE, of a substance and define each term.
$Δ E = m c Δ θ$
- ΔE = change in heat energy (J)
- m = mass (kg)
- c = specific heat capacity (J kg^-1 K^-1)
- Δθ = change in temperature (K or °C)
State the equation for the energy needed to change the state of a substance and define each term.
$Δ E = L Δ m$
- ΔE = energy to change state (J)
- L = specific latent heat of fusion or vaporisation (J kg^-1)
- Δm = change in mass of the substance changing state (kg)
Why does vaporising a mass of water need roughly seven times more energy than melting the same mass of ice?
Melting only needs enough energy to increase the separation between molecules so they can flow over each other. Vaporising needs enough energy to completely separate the molecules and overcome all the intermolecular forces between them, which requires much more energy.
The thermodynamic Kelvin temperature scale is an absolute scale where each degree is the same size as those on the .......... scale.
The thermodynamic Kelvin temperature scale is an absolute scale where each degree is the same size as those on the Celsius scale.
True or False?
Water has a low specific heat capacity, which is why it is used in radiators to heat homes.
False.
Water has a very high specific heat capacity, so it releases a large amount of energy as it cools, meaning it stays hot in a radiator for a long time.
What is the aim of Core Practical 12?
To calibrate a thermistor so that it can be used as a thermometer.
What are the independent and dependent variables in Core Practical 12?
- Independent variable: temperature (°C)
- Dependent variable: resistance of the thermistor (Ω)
How are the fixed resistor and ohm-meter connected relative to the thermistor in Core Practical 12?
The fixed resistor is connected in series with the thermistor, and the ohm-meter is connected in parallel across the thermistor to measure its resistance.
How are temperature and resistance readings taken across the full range in Core Practical 12?
Starting with the thermistor in ice, the water is heated with a Bunsen burner and stirred gently to keep the temperature even. Temperature and resistance are recorded at approximately 5 °C intervals until the water boils.
Give two ways to reduce systematic errors in Core Practical 12.
- Read the thermometer at eye level
- Check the zero error on the ohm-meter by connecting the leads across its terminals
In Core Practical 12, the water should be .......... gently at all times to keep the temperature as even as possible throughout the beaker.
In Core Practical 12, the water should be stirred gently at all times to keep the temperature as even as possible throughout the beaker.
True or False?
In Core Practical 12, the current should be left switched on between readings to save time.
False.
The current should be turned off between readings. Leaving it on would heat the wires and thermistor, introducing a random error into the resistance readings.
What is the aim of Core Practical 13?
To determine the specific latent heat of fusion of ice.
What are the independent and dependent variables in Core Practical 13?
- Independent variable: energy supplied by the heater, measured with a joulemeter (J)
- Dependent variable: temperature, T, of the ice/water (°C)
State the equation used to calculate the specific latent heat of fusion in Core Practical 13 and define each term.
$L = \frac{Δ E}{Δ m}$
- ΔE = energy supplied by the heater (J)
- L = specific latent heat of fusion
- Δm = mass of ice melted (kg)
How is Δm, the mass of ice melted by the heater, found in Core Practical 13?
$Δ m = m_{A} - m_{B}$
where m_A is the average mass of water collected from the heated funnel and m_B is the average mass of water collected from the unheated control funnel.
Give two ways to improve the accuracy of Core Practical 13.
- Apply lagging or insulation to the funnels and beakers to reduce energy lost to the surroundings
- Allow the heater to cool between readings so the rate of heating and starting temperature are the same each time
In Core Practical 13, ice must be measured into the beaker using a .......... rather than handled with bare hands.
In Core Practical 13, ice must be measured into the beaker using a spoon rather than handled with bare hands.
True or False?
Repeating Core Practical 13 several times and averaging the mass of melted ice reduces systematic errors.
False.
Repeating and averaging reduces random errors. Systematic errors, such as heat lost to the surroundings, must instead be reduced by insulating the apparatus.

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