C4-Chemical Changes

Question 1

Metal+oxygen —> ?

Answer 1

Metal oxides

Question 2

Oxidation is the … of oxygen

Answer 2

Gain

Question 3

Metals form…ions

Answer 3

Positive

Question 4

Displacement reaction

Answer 4

A reaction in which a more reactive element takes the place of a less reactive element.

Question 5

Ionic equation

Answer 5

An ionic equation is one that shows only those ions or atoms that change.

Question 6

Ions or atoms that don’t change in a chemical reaction are called…

Answer 6

Spectator ions

Question 7

Acids dissolved in water have a pH value of…

Answer 7

Less than 7, acids are proton H+ ion donors

Question 8

Acid + metal —>

Answer 8

Salt + hydrogen

Question 9

Hydrochloric acid

Answer 9

HCl -1

Question 10

Sulfuric acid

Answer 10

H₂SO₄

Question 11

Nitric acid

Answer 11

HNO₃ +1

Question 12

Redox reaction

Answer 12

When both oxidation and reduction occur

Question 13

How are soluble salts made?

Answer 13

By reacting acids with solid insoluble substances, such as metals, metal oxides, hydroxides or carbonates.

Question 14

Acid + base —>

Answer 14

Salt + water

Question 15

Alkalis

Answer 15

Have a pH value more than 7

Question 16

Acid + alkali —>

Answer 16

Salt + water

Question 17

Acid + metal carbonate —>

Answer 17

Salt + water + carbon dioxide

Question 18

Unit of concentration

Answer 18

Moles per decimetre cubed

Question 19

Strong acids are … ionised in an aqueous solution

Answer 19

Completely

Question 20

Weak acid is … ionised in an aqueous solution

Answer 20

Partially

Question 21

As the pH decreases by one unit, the hydrogen ion concentration of the solution…

Answer 21

Increases by a factor of 10

Question 22

Electrolysis

Answer 22

Breaks down ionic compounds (salts) into their elements using electricity.

Question 23

Cations

Answer 23

Positive ions

Question 24

Anions

Answer 24

Negative ions

Question 25

Anode

Answer 25

Positive electrode

Question 26

Cathode

Answer 26

Negative electrode

Question 27

At the cathode the ion of the …

Answer 27

Least reactive electron will be discharged.

Question 28

At the anode if a … is present that will be discharged over anything else.

Answer 28

Halide

Question 29

Ore

Answer 29

An ore is a material containing enough metal for it to be economically worth extraction.

Question 30

Quantative data

Answer 30

Measured empirically

Question 31

Qualitative data

Answer 31

Data collected by observation