C3.3 Types Of Chemical Reactions

Question 1

Reduction

Answer 1

Loss of oxygen from a substance

Oxidisation
Is
Loss of electrons
Reduction
Is
Gain of electrons

Question 2

Oxidisation

Answer 2

Gain of oxygen by a substance
Also:
Oxidisation
Is
Loss of electrons
Reduction
Is
Gain of electrons

Question 3

Oxidising agent

Answer 3

Substance that initially has the oxygen before the reaction

These accept electrons

Question 4

Reducing agent

Answer 4

Substance that initially does not have the oxygen before the reaction
These donate electrons

Question 5

Does a redox equation always involve oxygen

Answer 5

No

Question 6

Acids

Answer 6

Substances that release H+ ions when it dissolves in water to make an aqueous solution.

Question 7

Bases

Answer 7

Substances, usually metal hydroxides or metal oxides, that neutralise acids
If it dissolves in water, it is also called an alkali
Alkalis release OH- ions when they dissolve in water

Question 8

pH < 7

Answer 8

Acidic

Question 9

pH = 7

Answer 9

Neutral

Question 10

pH > 7

Answer 10

Alkaline

Question 11

Range of pH scale

Answer 11

0 to 14

Most acidic 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Most alkaline
I
Neutral

Question 12

What is neutralisation

Answer 12

Reaction between an acid and a base, or an alkali
Forms a salt and water

Question 13

Neutralisation equation

Answer 13

Acid + base -> salt + water

Question 14

How do you predict salt made from neutralisation

Answer 14

First part comes from the metal in the base or alkali
Exception: If ammonia or ammonium carbonate is used, name starts with ammonium

Second part of the name comes from the acid used such as
- Chloride (hydrochloride acid)
- Nitrate (nitric acid)
- Sulphate (sulphuric acid)

Question 15

What salt is formed with hydrochloride acid? (HCl)

Answer 15

Chloride

Question 16

What salt is formed with nitric acid? (HNO3)

Answer 16

Nitrate

Question 17

What salt is formed with sulfuric acid? (H2SO4)

Answer 17

Sulfate

Question 18

What salt is formed with phosphoric acid? (H3PO4)

Answer 18

Phosphate

Question 19

Predicting a neutralisation reaction

Answer 19

1) identify salt produced
2) write the word equation
3) Write balanced chemical formula underneath with state symbols

Question 20

What happens during neutralisation in solution

Answer 20

H+ ions from acidic solutions and OH- ions from alkaline solutions react to produce water.
H+(aq) + OH-(aq) -> H2O(l)

Salt produced depends on other ions present in the alkali and acid.

Question 21

What are carbonates

Answer 21

Ionic compounds that contain the carbonate ion CO3²⁻

Question 22

Reaction between acid and carbonate

Answer 22

Acid + carbonate -> salt + water + carbon dioxide

Question 23

What carbonates are soluble in water

Answer 23

Sodium carbonate
Ammonium carbonate
Group 1 metal carbonates

Question 24

Reaction between acids and metals

Answer 24

Acid + metal -> salt + hydrogen

Question 25

Dilute acid

Answer 25

Contains a low ratio of acid : volume of solution

Question 26

Concentrated acid

Answer 26

Contains a high ratio of acid : volume of solution

Question 27

Weak acid

Answer 27

partially ionised in solution of water Small fraction of their molecules release H+ ions

Question 28

Strong acid

Answer 28

completely ionised in solution of water All of their molecules release H+ ions

Question 29

⇌ symbol

Answer 29

Shows the reaction does not go to completion Reversible reaction

Question 30

What happens when the pH of a solution decreases by 1

Answer 30

Concentration of H+ ions increase by a factor of 10 Multiply by 10 Concentration of H+ ions decreases by a factor of 10 is pH increases by 1 Digide by 10

Question 31

pH titration curve

Answer 31

Shows effect on pH of changing the hydrogen ion concentration during a neutralisation reaction

Question 32

Acid, salt and negative ion of chlorine

Answer 32

Acid: Hydrochloric Salt: Chloride Negative ion: Cl ⁻ 2CI --> Cl2 + 2e- (anode)

Question 33

Acid, salt and negative ion of nitrogen

Answer 33

Acid: Nitric Salt: Nitrate Negative ion: NO₃

Question 34

Acid, salt and negative ion of sulfur

Answer 34

Acid: Sulfuric Salt: sulfate Negative ion: SO²⁻

Question 35

Acid, salt and negative ion of phosphorus

Answer 35

Acid: Phosphoric Salt: Phosphate Negative ion: PO₄³⁻

Question 36

What is formed when a group 1 metal reacts with water

Answer 36

Metal + water -> metal hydroxide + hydrogen

Question 37

More reactive metals displace…

Answer 37

Less reactive metals from their compounds.

Question 38

Reaction between acid and metal oxide

Answer 38

Acid + metal oxide -› salt + water Example: H2SO4(aq) + CuO(s) -› CuSO4(aq) + H2O(l)