C4 - Chemical Changes

Question 1

What is the ph scale

Answer 1

Measure of how acidic or alkaline a solution is

Question 2

The lower the ph of a solution the more

Answer 2

Acidic it is

Question 3

The higher the ph of a solution the more

Answer 3

Alkaline it is

Question 4

How can you measure the ph of a solution

Answer 4

An indicator is a dye that changes colour depending on whether it’s above or below a certain ph .They are useful for estimating the pH of a solution

Question 5

The reaction between acids and bases is called

Answer 5

Neutrlasation

Question 6

Metal oxides and metal hydroxides react with acids in neutralisation reactions to form

Answer 6

A salt and water

Question 7

Metal Carbonates are also bases.They react with acids to produce a salt ,

Answer 7

Water and carbon dioxide

Question 8

If you react an acid with an insoluble base or metal you can

Answer 8

Make a soluble salt

Question 9

What is oxidation

Answer 9

When metals react with oxygen to form oxides

Question 10

What is a reduction reaction

Answer 10

Oxides are often the ores that the metals are removed ( extracted ) from.A reaction that separates a metal from its oxide is called a reduction reaction

Question 11

Some metals can be extracted from their ores using a reaction with carbon.In this reaction,

Answer 11

The one is reduced as oxygen is removed from it .Carbon gains oxygen so it is oxidised

Question 12

Some metals react with acids to produce

Answer 12

A salt and hydrogen gas

Question 13

Very reactive metals such as potassium sodium react

Answer 13

Explosively with acids

Question 14

Less reactive metals such as magnesium react

Answer 14

Less violently