Introduction

Question 1

Define a chemical reaction

Answer 1

new product formed, usually irreversible

Question 2

Define a physical reaction

Answer 2

no new product formed, always reversible

Question 3

What are the signs of a chemical reaction?

Answer 3

colour change
irreversible (usually)
gas released
smell
temperature change
smoke
light given off
new product formed

Question 4

What are the signs of a physical reaction?

Answer 4

reversible (always)
change of state
dissolving
no new product formed

Question 5

What happens to atoms in a physical reaction?

Answer 5

atoms change arrangements

Question 6

What happens to atoms in a chemical reaction?

Answer 6

bonds break, rearrange, bond back together

Question 7

solid -> liquid?

Answer 7

melting

Question 8

liquid -> gas?

Answer 8

evaporating

Question 9

gas -> liquid?

Answer 9

condensing

Question 10

liquid -> solid?

Answer 10

freezing

Question 10

solid -> gas?

Answer 10

sublimation

Question 11

gas -> solid?

Answer 11

deposition

Question 12

What is an atom?

Answer 12

the smallest part of an element

Question 13

What is an element?

Answer 13

made up of one type of atom

Question 14

What is a molecule?

Answer 14

More than one atom chemically bonded

Question 15

What is a diatomic element?

Answer 15

Molecule of an element made of two atoms

Question 16

What are some examples of diatomic elements?

Answer 16

N, O, F and down

Question 17

What are the properties of metals?

Answer 17

shiny
solid at room temp (high mp)
conduct electricity
conduct heat
malleable
sonorous (make sound)

Question 18

What are the properties of non-metals?

Answer 18

dull
gas at room temp (not all)
non conductive
not malleable
not sonorous
low density
weak

Question 19

What is a metalloid?

Answer 19

Can have properties of metals and non-metals. Eg Silicon - non metal but can be made to conduct electricity

Question 20

What is a compound?

Answer 20

more than one type of atom chemically combined

Question 21

What is a mixture?

Answer 21

more than one substance not chemically combined

Question 22

What is the chemical test for the presence of water?

Answer 22

Anhydrous copper sulphate turns from white to blue
Cobalt chloride paper will turn from blue to pink

Question 23

How can you determine if water is pure or not?

Answer 23

measure boiling point - pure water boils at 100ºC

Question 24

What is diffusion?

Answer 24

movement of particles from an area of high to low concentration as a result of their random movement

Question 25

How can rate of diffusion be increased?

Answer 25

push particles around
increase temp
increase concentration

Question 26

What is a solvent?

Answer 26

The liquid that dissolves the solute

Question 27

What is a solute?

Answer 27

The solid that dissolves in the solvent

Question 28

What is a solution?

Answer 28

mixture of solvent and dissolved solute

Question 29

What does saturated mean?

Answer 29

no more solute is able to dissolve

Question 30

What does insoluble mean?

Answer 30

can not dissolve (in a certain solvent)

Question 31

What does soluble mean?

Answer 31

can dissolve (in a certain solvent)

Question 32

What is suspension?

Answer 32

Solution containing undissolved solid (normally floating)

Question 33

What are the unites to measure solubility?

Answer 33

g per 100g

Question 34

How would you separate a mixture of inks?

Answer 34

chromatography

Question 35

How would you separate Ethanol + water?

Answer 35

distillation

Question 36

How would you separate salt + water?

Answer 36

evaporation

Question 37

How would you separate sand + water?

Answer 37

filtration