States of matter

Question 1

What are the 3 laws of ideal gases?

Answer 1

1) There are no intermolecular forces betwen gases
2) The volume occupied by gas molecules is negligable (comparing with the volume of the container they are contained in)
3) Elastic collision (No loss of energy upon collision against the container)

Question 2

(Ideal gases) what is the relation between volume and pressure?

Answer 2

Inversely proportional.
As volume increases pressure decreases
As volume decreases pressure increases

Question 3

(Ideal gases) What is the relation between volume and temperature?

Answer 3

Directly proportional.
As volume increases so does temperature
As volume decreases so does temperature

Question 4

(Ideal gases) What is the relation between the no. of molecules?

Answer 4

Directly proportional.
As volume increases so does the no. of gas molecules
As volume decreases so does the no. of gas molecules

Question 5

What is the ideal gas equation?

Answer 5

Pv = nRT

Question 6

What is the ideal gas equation in relation to Molecular mass (Mr)?

Answer 6

Mr = mRT / Pv

Question 7

What is the ideal gas equation in relation to density?

Answer 7

density = PMr / RT

Question 8

What is the ideal gas equation in relation to concentration?

Answer 8

concentration = P / RT

Question 9

In what way do real gases not obey ideal gases assumptions? Explain your reasons. (3)

Answer 9

1) Low temp. :
>At low temp. gases slow down and can therefore form instantanious dipole - induced dipole forces (intermolecular forces)

2) High pressure:
>At high pressures, gases are ‘pushed’ closer together and can form instantanious dipole - induced dipole forces (intermolecular forces)

3) Negligance of particles volume:
> In some cases, if the volume of the container is small, the volume of the particles cannot be neglicted.

Question 10

State the units and how we get them in ideal gas equations

Answer 10

Pv = nRT
P = kPa –(x1000)–> Pa
v = dm^3 –( /1000 )–> m^3
R = constant (8.31 kJ-1 mol-1)
T = celcius –( +273 )–> Kelvin

Question 11

What is the relation between charge and bonding strength?

Answer 11

Directly proportional:
As charge increases, so does bond strength.

Question 12

Describe the how the ions surround one another in a giant ionic lattice

Answer 12

Each ion is surrounded by 6 other ions.

Question 13

Explain why anions are larger than cations in a giant ionic lattice

Answer 13

By cations giving their electrons to anions, anions cloud spreads out while cations are attracted closer to the nucleus (due to the attraction of positive protons and negative electrons)

Question 14

Can a giant ionic lattice conduct electricity? Why/ Why not and explain the reasoning.

Answer 14

No.
They can only conduct electricity when in a molten form, this is because in a molten form ions can move and carry an electric charge.

Question 15

Give 2 examples of a giant ionic lattice

Answer 15

MgO , NaCl , etc.

Question 16

Why are ionic solids brittle?

Answer 16

When applying a force, it brings the ions with the same charges parallel to each other, causing a repulsion which then breaks the lattice.

Question 17

Why are the ios in metallic lattices fixed?

Answer 17

Because of the mobile electrons around the ions.

Question 18

Why arent metals (metallic lattices) brittle?

Answer 18

Mobile e- allow for attraction even after forces are applied

Question 19

Why can graphite conduct electricity?

Answer 19

For every carbon in graphite, theres one electron free to move inbetween layers

Question 20

Why cant diamond conduct electricity?

Answer 20

All carbon atoms have all their electrons bonded with other carbon atoms, meaning there are no free valence electrons

Question 21

Why can graphite slide over one another?

Answer 21

Weak intermolecular forces are formed inbetween layers

Question 22

What is the simplest structure of a buckminsterfullerene?

Answer 22

C60