Properties of Matter Flashcards
What is heat energy measured in?
Joules (J)
Define temperature.
A measure of how hot a substance is.
What is temperature measured in?
Celcius (°C)
What does the heat energy required to change the temperature of a substance depend on?
- The change in temperature of the material
- The mass of the material
- The type of the material
Define the SPECIFIC HEAT CAPACITY.
The specific heat capacity is the amount of energy required to change the temperature of 1kg of a substance by 1°C.
What is the unit for specific heat capacity?
Joule Per Kilogram
(J/kg°C)
What is the formula for finding heat energy?
Eh = cm∆T
Eh - Heat Energy (J)
c - Specific Heat Capacity (J/kg°C)
m - Mass (kg)
∆T - Change in temperature (°C)
What can the change in temperature mean?
The change in temperature can mean:
- The amount of heat energy required to increase the temperature of an object
- The amount of heat energy given out by an object as it cools
What is the law of Conversation of Energy?
The Law of Conservation of Energy states that ENERGY CANNOT BE CREATED OR DESTROYED, BUT CAN BE CHANGED FROM ONE FORM INTO ANOTHER.
What graph can be plotted to show how temperature varies over time?
A cooling curve.
What happens when a material changes state FROM GAS TO LIQUID, or LIQUID TO SOLID?
Latent heat is released.
What is latent heat?
Latent heat is “hidden” heat. It describes the heat released or absorbed during a change of state.
It is the energy required to change the state WITHOUT a change in temperature.
What is the formula for the total heat energy required to change the state of a material?
Eh=mL
—
Eh - Heat energy (J)
m - Mass [that has changed state] (kg)
L - Specific Latent Heat of Material (Jkg–¹)
What is pressure?
The force per unit exerted on a surface.
What is pressure measured in?
Pascals (Pa)
[1 Pa = 1Nm–²]
(1Nm-2 = 1 Newton per Metre²)
How is pressure affected when weight is concentrated on a very small area?
Larger pressure
How is pressure affected when weight is concentrated on a large area?
Smaller pressure
What is the formula to calculate pressure?
P = F/A
—
P - Pressure (Pa)
F - Force (N)
A - Area (m²)
How is pressure affected as the volume of a gas reduces?
Pressure increases.
(As long as temperature and amount remain constant)
P (pressure) and V (volume) are ___ ___. When one doubles, the other is ____ by half.
Inversely Proportional
Reduced
How to calculate final pressure and final volume using the comparison of a fixed mass of gass at different pressures or volumes?
P1V1 = P2V2
—
P1 - Initial Pressure (Pa)
V1 - Initial Volume (m³)
P2 - Final Pressure (Pa)
V2 - Final Volume (m³)
What will happen as volume is reduced?
The particles will hit the walls of the container more often.
This causes a LARGER FORCE to act on the walls of the container.
From P = F/A, this causes the pressure of the gas to increase.
How do you convert Celcius (°C) to Kelvin (K)?
Add 273°c
How do you convert Kelvin (K) to Celcius (°C)
Subtract 273
How is pressure affected as the temperature of a gas increases?
Pressure increases
What is the relationship between pressure and temperature?
Pressure and temperature are proportional to each other.
What does it mean if a graph of pressure against temperature in Kelvin gives a straight line?
It means that PRESSURE and TEMPERATURE IN KELVIN are DIRECTLY PROPORTIONAL.
How to calculate final pressure and final temperature using the comparison of a fixed mass of gass at different pressures or temperatures?
P1/T1 = P2/T2
—
P1 - Initial Pressure (Pa)
T1 - Initial Temperature (K)
P2 - Final Pressure (Pa)
T2 - Final Temperature (K)
As the temperature of a gas is increased, what is increased?
As the temperature of a gas increases, the average kinetic energy of the particles increases.
The particles speed up and therefore hit the walls of the container harder and more often.
P=F/A means that the pressure of the gas will increase.
How is volume affected as the temperature of a gas is increased?
Volume increases
What is the relationship between volume and temperature?
Volume and temperature are proportional to each other.
What is the relationship between volume and temperature in Kelvin?
Directly proportional.
How to calculate final temperature and final volume using the comparison of a fixed mass of gass at different temperatures or volumes?
V1/T1 = V2/T2
—
V1 - Initial Volume (m³)
T1 - Initial Temperature (K)
V2 - Final Volume (m³)
T2 - Final Temperature (K)
Explain how the increase in temperature of a gas increases volume.
As the temperature of the gas is increased, the average kinetic energy of the particles increases.
The particles will speed up and hit the walls of the container harder and more often.
This means there will be a greater force acting on the walls of the container, and the container walls will often expand, resulting in an increase in volume.
Explain how the increase in temperature of a gas causes the pressure of the gas to increase.
As the temperature of the gas is increased, the average kinetic energy of the particles is increased.
The particles speed up and hit the walls of the container harder and more often.
From P=F/A, this causes the pressure of the gas to increase.
Explain how a reduction in volume of a gas increases the pressure of the gas?
As volume is reduced, the particles will hit the walls of the container more often.
This means that there will be a larger force acting on the walls of the container.
From P=F/A, this causes the pressure of the gas to increase.
What is the formula for the general gas law?
P1V1/T1 = P2V2/T2
—
P1 - Initial Pressure (Pa)
V1 - Initial Volume (m³)
T1 - Initial Temperature (K)
P2 - Final Pressure (Pa)
V2 - Final Volume (m³)
T3 - Final Temperature (K)
Give two examples of applications of the General Gas Law.
- Gas in scuba diving breathing apparatus. Gas is under high pressure to allow more to be stored. (P & V)
- Refrigerators. Compression heats refrigerants, expansion cools it, enabling heat transfer to keep the fridge cold (T)
What is Boyle’s Law?
Boyle’s Law states that for a gas at a constant temperature, pressure and volume will remain inversely proportional.
pV = k
What is the formula for Boyle’s law?
pV = k
———
p = Pressure
V = Volume
k = A constant
What is Charles’ law?
Charles law states that the volume of an ideal gas is directly proportional to the absolute temperature at constant pressure.
