Key Words

Question 1

Acid

Answer 1

An acid is a solution with pH less than 7

Question 2

Alkali

Answer 2

An alkali is a soluble base

Question 3

Base

Answer 3

A base is a substance that neutralises an acid but unlike an alkali it is not soluble.

Question 4

Concentrated

Answer 4

A solution is concentrated if it has a large number of solute particles per unit volume (litre or cube meter)

Question 5

Corrosive

Answer 5

A substance is corrosive if it can burn your skin or eyes

Question 6

Dilute

Answer 6

A solution is dilute if it has a small number of solute particles per unit volume (litre or cubic meter)

Question 7

Indicator

Answer 7

A substance that changes colour to show wether a solution is acidic or alkaline

Question 8

Litmus

Answer 8

An indicator blue litmus paper goes red on adding acid red litmus paper goes blue on adding alkali

Question 9

Neutral

Answer 9

A solution that is neither alkaline nor acidic it’s pH is 7

Question 10

Neutralisation

Answer 10

In a neutralisation reaction an acid cancels out a base or a base cancels out an acid

Question 11

pH scale

Answer 11

The pH scale shows wether a substance is acidic alkaline or neutral an acid has a pH below 7 an alkaline solution has a pH above 7 a solution of pH 7 is neutral

Question 12

Salt

Answer 12

A salt is a compound in which the hydrogen atoms of an acid are replaced by atoms of metal element

Question 13

Universal indicator

Answer 13

An indicator that changes colour to show the pH of a solution