1. The fundamental ideas of chemistry

Question 1

What is the state change from solid to liquid?

Answer 1

Melting

Question 2

Liquid to gas?

Answer 2

Evaporation

Question 3

Gas to liquid?

Answer 3

Condensation

Question 4

Solid to gas?

Answer 4

Sublimation

Question 5

Gas to solid?

Answer 5

Sublimation

Question 6

Features of a solids

Answer 6

Tightly arranged in a lattice
Dense
High intermolecular forces of attraction
Vibrating
Low energy

Question 7

Features of liquids

Answer 7

Free flowing particles (ions)
Change the shape to that of the container
Randomly arranged
Slightly weaker intermolecular forces of attraction

Question 8

Features of Gasses

Answer 8

Particles arranged randomly
Move randomly filling the space
Very weak/no intermolecular forces of attraction
Not very dense (spaced out)
free to move
High energy

Question 9

liquid to solid?

Answer 9

Freezing/liquefaction

Question 10

(s)

Answer 10

Solid

Question 11

(l)

Answer 11

liquid

Question 12

(g)

Answer 12

gas

Question 13

(aq)

Answer 13

in solution of water

Question 14

How do you calculate percentage yield?

Answer 14

(actual mass made/expected mass) x 100

Question 15

Why won’t you get 100% yield?

Answer 15

Reaction might be reversible
Product lost when it’s separated from reaction mixture
Impurities in reactants
Reactants might react in unexpected ways

Question 16

What is Brownian motion and diffusion?

Answer 16

The theorem that fluid particles will spread out until they reach an even distribution

Question 17

What is the link between temperature and rate of reaction?

Answer 17

Higher the temperature the higher the rate of reaction

Question 18

What will diffuse faster, a more or a less dense gas?

Answer 18

The less dense gas

Question 19

Which experiment proves particle theory?

Answer 19

The experiment with Ammonia (NH3) and HCl where a white precipitate is formed in a glass tube

Question 20

What is an Atom?

Answer 20

The smallest indivisible particle

Question 21

What is an Element?

Answer 21

A substance made of one type of atom chemically joined together
Found on the Periodic Table & represented by symbols

Question 22

What is the relative charge and atomic mass of a Proton?

Answer 22

Relative charge = +1 Relative mass = 1

Question 23

How do you calculate the percentage mass of an element in a compound?

Answer 23

(Ar x Number of atoms of the element) / (Mr of whole compound) x 100

E.g. Fe2O3
(16 x 3) / (56 x 2 + 16 x 3) x 100
30% Oxygen

Question 24

How do you calculate the Empirical Formula, from masses or percentages?

Answer 24

experimental mass or percentage / Ar
Turn the numbers into a simple ratio
Get the ratio it its simplest form

Question 25

How do you calculate the mass of substances in reactions?

Answer 25

Write out the balanced equations
Work out the Mr (for bits you want)
Divide to get one, then multiply to get all

Question 26

What is the definition of diffusion?

Answer 26

It is the gradual movement of particles, from highly concentrated areas to areas of low concentration

Question 27

Give three experiments to show diffusion

Answer 27

Potassium Mangante VII (KMnO4)
Place in beaker of water, purple colour will diffuse
Shows random motion of particles in a liquid
Br2 gas and air, brown colour will diffuse evenly
NH3 (aq) and HCl in tube, white ring formed