Unit 2.2: Acids, bases and salts

What is an Alkaline solution

A base that dissolves in water and has a pH higher than 7

What is the pH of a neutral solution

7

What is an acid

A solution that has pH level lower than 7

What ion do alkaline contains

OH-, hydroxide ions

What is a strong acid

An acid which completely dissociate to release H+ ions in an aqueous solution

What is a weak acid

An acid which partly dissociate to release H+ ions in an aqueous solution

What is a strong alkaline

An alkaline which completely dissociate to release OH- ions in an aqueous solution

What is an weak alkaline

An alkaline which partly dissociate to release OH- ions in an aqueous solution

What is the product formed when a metal is added to a dilute acid. And how does the metal’s reactivity affect the rate of reaction

Metal + Acid ——> Salts + Hydrogen.

Generally, the more reactive the metal is, the faster the rate of reaction is

State the 2 neutralisation reaction

1. Acid + Alkaline/base ——> Salt + Water

2. Acid + Metal carbonate ——> Salts + Water + Carbon Dioxide

What is neutralisation

The reaction of hydrogen ions from acid and hydroxide ions from alkaline to form a pure water substance with a pH level of 7

State how to test for the presence of carbonate [2]

1. Carbonate will react with dilute acid to form carbon acid

2. The gas can be bubbled through limewater, and if the limewater turn milky it is carbon dioxide

How can soluble salts be produced

Acid reacting with insoluble substances like metal, metal oxide, hydroxide or carbonate

What are the names of salts formed from hydrochloric acid, nitric acid and sulfuric acid?

• Hydrochloride acid = chloride

• Nitric acid = Nitrate

• Sulfuric acid = Sulfates

What is the test for sulfate ions

Precipitation reaction. First add dilute hydrochloride acid , followed by barium chloride solution, then a white precipitate will form if sulfate ions is present

What is titration used for

Titration is a method to prepare solution of soluble salts, and it is used to determine the relative and the actual concentration of acid/alkaline

State the 2 mole equation

Mole = Mass/RAM

Mole = Concentration*Volume

How to convert from cm³ to dm³

/1000

State the 2 way to measure pH level of a substance

1. Universal indicator

2. pH probe

Acid + Metal Oxide ——>

Salt + Water

Acid + Metal Hydroxide ——>

Salts + Water

Acid + Metal ——>

Salt + Hydrogen

Acid + Metal Carbonate

Salt + Water + Carbon Dioxide

How to prepare a soluble salt from an insoluble base or carbonate

Copper oxide = insoluble base

1. Measure 25cm³ of sulphuric acid into a beaker

2. Put the beaker into a second baker of hot water that is above burning Bunsen Burner

3. Add 1 spatula of copper oxide to sulphuric acid and stir

4. Add more spatula of copper oxide until all acid has reacted

5. Filter solution to remove unreacted copper oxide

6. Pour the solution into a clean evaporating dish, and heat it to concentrated liquid

7. Leave the evaporation dish on a window until crystal form

How to make bigger and smaller crystals in this practical: “Preparing of a soluble salt from an insoluble base or carbonate”

Bigger crystal = Heat slowly

Small Crystal = Heat quickly