Formulae And Equasions (topic 2)

Question 1

Nitrogen

Answer 1

N2

Question 2

Oxygen

Answer 2

O2

Question 3

Fluorine

Answer 3

F2

Question 4

Chlorine

Answer 4

Cl2

Question 5

Bromine

Answer 5

Br2

Question 6

Iodine

Answer 6

I2

Question 7

Astatine

Answer 7

At2

Question 8

Phosphorus

Answer 8

P4

Question 9

Sulphur

Answer 9

S8

Question 10

Define an element

Answer 10

An element is a simple substance that cannot be made simpler by chemical means - contains 1 type of atom

Question 11

Define a compound

Answer 11

A compound is a substance made from 2 or more elements that have been chemically combined

Question 12

Metal + oxygen

Answer 12

Metal oxide

Question 13

Metal + fluorine

Answer 13

Metal fluoride

Question 14

Metal +chlorine

Answer 14

Metal chloride

Question 15

Metal + iodine

Answer 15

Metal iodide

Question 16

Metal + sulphur

Answer 16

Metal sulphide

Question 17

Metal + nitrogen

Answer 17

Metal nitrate

Question 18

Metal + phosphorus

Answer 18

Metal phosphide

Question 19

Metal + hydrogen

Answer 19

Metal Hydride

Question 20

Do metals have positive or negative valencies

Answer 20

Metals have positive valencies

Question 21

Do non-metals have positive or negative valencies

Answer 21

Non-metals have negative valencies

Question 22

When writing out the formula of a compound , the valencies need to add up to

Answer 22

Zero (eg +3 -3)

Question 23

If valencies are uneven, can you add molecules

Answer 23

Yes, as long as you have the same number of atoms on each sides (eg +3 -1-1-1)

Question 24

Metal + sulphur + oxygen

Answer 24

Metal sulphate

Question 25

Compounds with oxygen are usually

Answer 25

Ates . Eg (metal + other + oxygen --> metal otherATE)

Question 26

Water

Answer 26

H2O

Question 27

Ammonia

Answer 27

NH3

Question 28

Methane

Answer 28

CH4

Question 29

Nitric acid

Answer 29

NHO3

Question 30

Sulphuric acid

Answer 30

H2SO4

Question 31

Hydrochloric acid

Answer 31

HCl

Question 32

What does the small number next to a letter represent

Answer 32

How many atoms there are of each element (eg K4 would be 4 potassiums)

Question 33

Reactant

Answer 33

What are being reacted together

Question 34

Products are

Answer 34

What the reactants produce

Question 35

A big number in front of a formula ...

Answer 35

Multiplies every symbol that follows it (eg 2HCl = 2H + 2Cl)

Question 36

What happens in a displacement reaction

Answer 36

Two metal are 'competing' for the non-metal. The metal that is higher up in the reactivity series 'takes' the non-metal

Question 37

What should a description have ?

Answer 37

A colour (blue, green, transparent) and a state (liquid,solid, gas)

Question 38

Formulae equations should include state symbols. What are they ?

Answer 38

s - solid aq - aqueous solution g - gas l - pure liquid

Question 39

What is a solution

Answer 39

A solution is a solid dissolved in a liquid (eg salt water)

Question 40

What do you do if there is no reaction ?

Answer 40

Put a cross through the arrow and write no reaction | eg iron +calcium carbonate -/-> no reaction

Question 41

What is a direct combination

Answer 41

When 2 or more elements combine to give a single product (valencies still have to match) Eg calcium + oxygen --> calcium oxide 2Ca +O2 --> 2CaO

Question 42

What is thermal composition?

Answer 42

When you add heat / fire, the element or compound is combined with oxygen

Question 43

metal carbonate (+heat) -->

Answer 43

Metal oxide + carbon dioxide | Carbonates of potassium and sodium do not decompose

Question 44

Metal hydroxide (+heat) -->

Answer 44

Metal oxide + water | Hydroxides of potassium or sodium do not decompose

Question 45

Metal nitrate (+heat) -->

Answer 45

Metal oxide + nitrogen dioxide + oxygen

Question 46

Test for nitrogen dioxide (a brown gas)

Answer 46

Blue litmus paper turns red

Question 47

Test for carbon dioxide

Answer 47

Bubble through limewater, it turns milky

Question 48

Test for water vapour

Answer 48

Anhydrous copper sulphate turns from white to blue

Question 49

Precipitation reaction

Answer 49

Two soluble compounds are separately dissolved in water and then the two solutions are mixed together. If the cations (positive ions) swap anion (negative ions) to form an insoluble compound then a precipitate will be formed

Question 50

What is a precipitate

Answer 50

A precipitate is an insoluble substance produced during a reaction (shortened to ppt)

Question 51

Solubility of sodium, potassium, and ammonium compounds

Answer 51

They are all soluble

Question 52

Solubility of nitrates

Answer 52

Soluble (except silver chloride me lead chloride in cold water)

Question 53

Solubility of sulphates

Answer 53

Soluble (except barium sulphate, calcium sulphate and strontium sulphate)

Question 54

Solubility of carbonates

Answer 54

Insoluble

Question 55

Solubility of hydroxides / oxides

Answer 55

Insoluble

Question 56

What is PH neutral

Answer 56

7 (green)

Question 57

What is PH strong acid

Answer 57

1,2 (red)

Question 58

What is medium acid

Answer 58

3 (red) and 4 (orange)

Question 59

What is PH weak acid

Answer 59

5 (orange) and 6 (yellow)

Question 60

What is PH weak alkali

Answer 60

8 (greenish blue) and 9 (purple)

Question 61

What is PH medium alkali

Answer 61

10 (purple) and 11 (blue)

Question 62

What is PH strong alkali

Answer 62

12, 13 (blue) and 14 (black)

Question 63

Formula for hydrogen

Answer 63

H2