4. States of matter

Question 1

explain the origin of pressure in a gas

Answer 1

collisions between gas molecules and the wall of the container

Question 2

ideal gases

Answer 2

S- ideal gases have zero particle volume and no intermolecular forces of attraction

*no VdW forces present/ no force of attraction between particles.
* ideal gas particles have no/negligible volume compared to container.
*collisions between ideal gas particles/walls of container are perfectly elastic.
*ideal gas particles behave as rigid spheres.

Question 3

ideal gas equation and using it to find Mr.

Answer 3

pV = nRT

pressure- Pa
volume- m^3
no. of moles- mol
gas constant- 8.31 JK^-1mol^-1
temperature- K

0°C + 273.15 = 273.15K

Question 4

conditions at which a gas behaves most like an ideal gas

Answer 4

low pressure and high temperature

• volume of particles is negligible compared to volume of container
• VdW forces are insignificant owing to high kinetic energy of particles.

Question 5

giant ionic- lattice structure of a crystalline solid

Answer 5

ex- sodium chloride magnesium oxide

Question 6

giant molecular- lattice structure of a crystalline solid

Answer 6

ex- silicon(IV) oxide, graphite and diamond

Question 7

simple molecular- lattice structure of a crystalline solid

Answer 7

ex- iodine, buckminsterfullerene C60 and ice

Question 8

giant metallic- lattice structure of a crystalline solid

Answer 8

ex- copper

Question 9

describe, interpret and predict the effect of different types of structure and bonding on the physical properties of substances, including melting point, boiling point, electrical conductivity and solubility

Question 10

deduce the type of structure and bonding present in a substance from given information