chapter 14

Question 1

Oxidation Reaction

Answer 1

When a substance reacts with oxygen.

Question 2

Neutralisation Reaction

Answer 2

An acid and a base reacting to form salt and water.

Question 3

Electrolysis Reaction

Answer 3

Produced by electricity or produces electricity.

Question 4

Decomposition Reaction

Answer 4

Breaking down a substance into simpler compounds.

Question 5

Law of Conservation of Mass

Answer 5

In a reaction the total mass of reactants always equals the total mass of the products.

Question 6

Hydrocarbon

Answer 6

A compound that contains hydrogen and carbon.

Question 7

Testing for Oxygen in the Air

Answer 7

Copper turnings are put in silicia glass tubing with a gas syringe at each end. As they are heated using a bunsen burner, air is passed over them using syringes. Copper + Oxygen = Copper Oxide.
Observed that approximately 20cm cubed of air used up, i.e: Air contais 20% oxygen.

Question 8

The Fire Triangle

Answer 8

1. Fuel
2. Heat
3. Oxygen

Question 9

Incomplete combustion of fuel word equation

Answer 9

Fuel (hydrocarbon) + oxygen = carbon monoxide + water

Question 10

Incomplete combustion of fuel

Answer 10

When there is not enough oxygen for complete combustion of fuel the reaction will not be completely finished.

Question 11

Carbon Monoxide (CO)

Answer 11

Colourless, odourless, toxic gas

Question 12

Preventing poisoning by carbon monoxide

Answer 12

Boilers should be regularly serviced.
Rooms should be well ventilated.
Carbon monoxide detectors should be installed.

Question 13

Metal + Water = Metal oxide/metal hydroxide and hydrogen

Answer 13

Metal oxide/metal hydroxide and hydrogen

Question 14

Sodium + Water=

Answer 14

Sodium hydroxide + Hydrogen

Question 15

Metal + Oxygen=

Answer 15

Metal oxide

Question 16

Magnesium + Oxygen=

Answer 16

Magnesium Oxide

Question 17

Corrosion

Answer 17

The gradual reaction of metals with water and oxygen in their environment. A metal oxide is formed.

Question 18

Corrosion of iron

Answer 18

Iron oxide is formed (red) on the surface of the metal but this flakes off allowing iron underneath to be corroded further. Oxygen and water are both neede for iron to corrode.

Question 19

Preventing Corrosion

Answer 19

1. Painting the metal
2. Covering metal with plastic coating
3. Greasing moving parts of metal with oil.
4. Galvinising: Covering with thin layer of a metal that doesn’t rust, e.g chromium, zinc.

Question 20

Reactivity Series of Metals

Answer 20

Scientists use this to show metals in order of reactivity, e.g: if they react with water they are very reactive, but if they won’t react with oxygen they are very unreactive.

Question 21

One reason why Gold, Platinum and Silver are so valuable

Answer 21

They are unreactive and will never corrode. They remain shiny.

Question 22

Ion

Answer 22

A charged atom.

Question 23

Ionic Bond

Answer 23

A force of attraction between two oppositely charged ions in a compound.

Question 24

Covalent Bond

Answer 24

Formed when pairs of electrons are shared between two atoms.

Question 25

Coefficient

Answer 25

The number in front of the formula which indicates the tital number of molecules or ions of each kind involved in the reaction.

Question 26

Subscript

Answer 26

The number to the lower right of the chemical symbol which indicates the number of atoms of that element found in the compound.

Question 27

Valency

Answer 27

The combining power of the element. It is the number of bonds that elements need to form in a compound.

Question 28

Fuel (hydrocarbon) + oxygen =

Answer 28

carbon dioxide + water