States of Matter Flashcards
Describe the arrangement and properties of gases?
Gases have no fixed shape or volume.
They are far apart so can be compressed
Are randomly arranged
Can move freely from place to place in all directions.
Describe the arrangement and properties of liquids.
Liquids have no fixed shape but fixed volume.
Are close together, so liquids have a fixed volume and can only be compressed slightly.
Are randomly arranged
Have limited movement from place to place in all directions.
Describe the arrangement and properties of solids.
Solids have a fixed volume and shape.
They are usually in a regular arrangement.
Are touching each other so cannot be compressed.
Cannot change positions with each other, they can only vibrate.
What does the state of a substance at room temperature depend upon?
The state of a substance at room temperature depends upon its structure and bonding.
What are the four types of structures and bonding found in elements or compounds?
Simple molecular or simple atomic for e.g. CO2, Argon and noble gases.
Giant Ionic e.g. Sodium Chloride and Magnesium chloride.
Giant metallic e.g. Iron and Copper.
Giant molecular e.g Silicon (IV) Dioxide.
Define an ideal gas:
Ideal gas is a gas whose volume varies in proportion to the temperature and in inverse proportion to the pressure. Ideal gases have no intermolecular forces of attraction and zero particle volume. Noble gases approach ideal behaviour because of their low intermolecular forces.
Define a real gas.
A gas that does not obey the ideal gas law especially at low temperatures and high pressures.
What is the pressure of a gas due to?
The pressure of a gas is due to the collisions between the gas molecules and the wall of the container.
Explain the relationship between pressure and volume of a gas.
If we decrease the volume of a gas (at constant temperature) the molecules come close together and hit the walls of the container more often, so the pressure of the gas increases. THEREFORE the pressure and volume of a gas are inversely proportional to each other as long as the temperature and the quantity of the gas are kept constant.
How can the relationship between pressure and volume be represented mathematically?
The relationship between pressure and volume (at constant mass and temperature) can be represented mathematically as:
V ∝ 1/P
v=k/p where k is a constant
PV=K
Under what conditions will a molecule most likely behave as an ideal gas?
High Temperature because energetic particles can easily break intermolecular forces/easier to behave as a gas.
Low pressure as the particle are far apart and there would be a large gap between the molecules so volume would be negligible as compared to volume of container.
How can you change celsius into kelvin?
To change Celsius to Kelvin, add 273 to the celsius temperature.
What is the pressure of 101 325 Pascals in atmospheric pressure?
101 325 Pa=1.0 atmospheric pressure.
Explain the relationship between temperature and volume at a constant pressure.
When a gas is heated at constant pressure its volume increases. This is because the particles move faster and hit the walls of the container with greater force. For the pressure to be constant, the molecules must be further apart. For this volume increases.
How can the relationship between volume and temperature be expressed mathematically?
For an ideal gas:
V∝T (at constant pressure)
What is the ideal gas equation?
PV=nRT
where
P=pressure in Pa
v=volume in m3
n=number of moles (also known as Avogadro’s constant)
R=Molar gas constant
T=temperature in kelvin
What is the value of molar gas constant?
R=8.314 J K-1 Mol-1
How can volume be converted into its si base units from cm3 and dm3?
Volumes si base unit is m3.
1000cm3=1dm3
1000dm3=1m3
1cm3=10^-6m3
150dm3=150 x 10^-3m3
