C2.6 Acids, bases and salts

Question 1

What does the state symbol (s) mean?

Answer 1

Solid

Question 2

What does the state symbol (l) mean?

Answer 2

Liquid

Question 3

What does the state symbol (g) mean?

Answer 3

Gas

Question 4

What does the state symbol (aq) mean?

Answer 4

Aqueous- dissolved in water

Question 5

What is an acid?

Answer 5

A substance with a pH less than 7

Question 6

What do acids form in water?

Answer 6

H+ ions

Question 7

What is a base?

Answer 7

A substance with a pH greater than 7

Question 8

What is an alkali?

Answer 8

A base that dissolves in water

Question 9

What do alkalis form in water?

Answer 9

OH- ions

Question 10

H+ ions make a solution…

Answer 10

Acidic

Question 11

OH- ions make a solution…

Answer 11

Alkaline

Question 12

Acid + Base =

Answer 12

Salt + Water

Question 13

What is the reaction between acids and bases called?

Answer 13

Neutralisation

Question 14

Metals react with acids to give…

Answer 14

Salts

Question 15

Acid + Metal =

Answer 15

Salt + Hydrogen

Question 16

What will hydrochloric acids always form?

Answer 16

Chloride salts

Question 17

What will sulfuric acid always form?

Answer 17

Sulfate salts

Question 18

The more reactive the metal reacted with the acid…

Answer 18

The faster it will go

Question 19

Which metal doesn’t react with acids to form salts?

Answer 19

Ones less reactive than hydrogen e.g. copper

Question 20

What are metal oxides metal hydroxides?

Answer 20

Bases

Question 21

Acid + Metal Oxide =

Answer 21

Salt + Water

Question 22

Acid + Metal Hydroxide =

Answer 22

Salt + Water

Question 23

What decides the salt?

Answer 23

The combination of the metal and acid
e.g. Hydrochloric acid + copper oxide ==> copper chloride + water
Hydrochloric acid + sodium hydroxide ==> sodium chloride + water

Question 24

Nitric acid produces…

Answer 24

Nitrate salts when neutralised with alkalis (but with metals it forms oxides)

Question 25

What does ammonia and nitric acid make?

Answer 25

Ammonium nitrate

Question 26

What can ammonium nitrate be used for?

Answer 26

Making fertiliser, it can neutralise soil and contains nitrogen which plants need to make proteins

Question 27

How do you make a salt using a metal or insoluble base?

Answer 27

Crystalisation

Question 28

How do you make a salt using an alkali?

Answer 28

Add the right amount of alkali to neutralise the acid then when it is finished use crystalisation

Question 29

How do you make an insoluble salt?

Answer 29

Precipitation reaction

Question 30

What is crystallisation?

Answer 30

You mix the two reactants and wait till they have reacted. Once they have reacted you filter out the excess solids leaving just the desired solution. You then heat the solution partly to evaporate the water, then you leave the water to evaporate naturally and slowly. You will be left with crystals

Question 31

What is a precipitation reaction?

Answer 31

Mix the two solutions. Once the salt has precipitated out an dis lying at the bottom of the flask you filter it out from the solution, wash it and dry it

Question 32

Soluble hydroxides are...

Answer 32

Alkalis

Question 33

What can precipitation be used for?

Answer 33

Removing unwanted ions from solutions e.g. treating dri

Question 34

What is the pH scale?

Answer 34

The measure of the acidity or alkalinity of a solution

Question 35

H2+ (aq) + OH- (aq) =====>

Answer 35

H2O (l)