Key Area 1.7 - Acids And Bases

Question 1

Describe an acidic solution

Answer 1

pH between 1 and 6
This is because they have a greater concentration of H+ ions than OH- ions
All acids contain H+ ions therefor all acids contain free mobile ions allowing them to conduct electricity and carry a charge

Question 2

Give examples of acids

Answer 2

Hydrochloric acid
Sulphuric acid
Nitric acid
Ethanoic acid

Question 3

Describe an alkaline solution

Answer 3

pH between 8 and 14
This is because they contain more OH- ions than H+ ions
All alkanes contain OH- ions and can conduct electricity because they have ions which are free to carry a charge

Question 4

Give examples of alkalis

Answer 4

Sodium hydroxide
Calcium hydroxide
Lithium hydroxide

Question 5

What happens when an acid or an alkali is diluted

Answer 5

Acid - the concentration of H+ ions decreases and the pH increases towards 7
Alkali- the concentration of OH- ions decreases and the pH decreases towards 7

Question 6

How can acids and alkalis be made

Answer 6

Acids and alkalis can be formed by dissolving different oxides in water

Question 7

What happens when a non metal oxide is dissolved

Answer 7

Non metal oxide gives an acidic solution

Question 8

What happens when a soluble metal oxide is dissolved in water

Answer 8

An alkaline solution is produced when the Base is dissolved in water

Question 9

What is a neutral solution

Answer 9

A neutral solution has an equal number of H+ ions and OH- ions which cancel each other out, because of the small amount of ions the water can conduct electricity.

Question 10

What is neutralisation

Answer 10

Neutralisation is there action if an acid with a base such as an alkali, metal oxide, metal hydroxide or carbonate.
ALL neutralisation reactions produce water

Acid + alkali -> salt + water
Acid + base -> salt + water
Acid + carbonate -> salt + water + carbon dioxide

The name if the salt produced is dependant on the acid and alkali reacted

Question 11

It’s the important acid names and their salt name ending

Answer 11

Hydrochloric acid - CHLORIDE
Sulphuric acid - SULPHATE
Nitric acid - NITRATE

Question 12

What are spectator ions

Answer 12

Spectator ions are ions that are present during the reaction but are unchanged by the reaction taking place.
Carbon dioxide and water are neutral and so do not have an ionic formula

Question 13

What is a titration

Answer 13

An acid-base titration us a procedure which is used to determine the concentration of an acid.
An measured volume of a base of a known concentration is reacted with an acid until the acid is neutralised.
An indicator is usually added to provide a colour change at the point when the neutralisation is complete
.. NEVER YSE THE ROUGH TITRE..

Question 14

What type of reaction produces insoluble salts

Answer 14

Precipitation reactions

Question 15

List the properties of acid

Answer 15

Acids are corrosive meaning when they react with something solid they will break up that substance causing the solid to be damaged.ALL acids can be corrosive if they are concentrated enough

Question 16

How is acid rain formed

Answer 16

Pollution can cause acid rain
Acid rain is formed when carbon dioxide, sulphur dioxide and nitrogen dioxide (formed the burning of fossil fuels) dissolving into the rain water

Question 17

What is the pH scale

Answer 17

The pH scale gives us an indication of how acidic or alkaline a substance is and the scale is continuous from below 0 to above 14. Potential of Hydrogen
pH below 7 - acidic solution, red/orange/yellow universal indicator
pH above 7 - alkaline solution, blue/purple universal indicator
pH of 7 - neutral solution, green universal indicator