C5 Chemical Changes

Question 1

What are ores?

Answer 1

Metals in their raw materials.

Question 2

What is the order of the reactivity series?

Answer 2

Potassium, K.
Sodium, Na.
Lithium, Li.
Calcium, Ca.
Magnesium, Mg.
Aluminium, Al.
Zinc, Zn.
Iron, Fe.
Tin, Sn.
Lead, Pb.
Copper, Cu.
Silver, Ag.
Gold, Ag.
Platinum, Pt.

Question 3

What is a displacement reaction?

Answer 3

When a more reactive substance displaces a less reactive metal from an aqueous solution of its salts.

Question 4

What is reduction and oxidation?

Answer 4

Oxidation=loss of electrons.

Reduction=gain of electrons.

Question 5

How do you know whether it is worth extracting a particular metal depend on?

Answer 5

Ease of extraction from its ore.
Quantity of metal ore contains.
Changing demands for particular metal.

Question 6

What is the order of the reactivity series with Carbon and Hydrogen?

Answer 6

Potassium, K.
Sodium, Na.
Lithium, Li.
Calcium, Ca.
Magnesium, Mg.
Aluminium, Al.
Carbon, C.
Zinc, Zn.
Iron, Fe.
Tin, Sn.
Lead, Pb.
Hydrogen, H.
Copper, Cu.
Silver, Ag.
Gold, Au.
Platinum, Pt.

Question 7

What is the equation for a metal that is > reactive than hydrogen reacting with an acid?

Answer 7

Metal + acid = Salt + Hydrogen.

Question 8

What does the salt produced depend on?

Answer 8

The metal used as well as acid used.

Question 9

What do you get when you react an acid with a base?

Answer 9

A salt + water.

Question 10

What is an alkali?

Answer 10

An alkali is a base that dissolves in water.

Question 11

How do you collect a pure dry sample of crystals of the salt?

Answer 11

Carry out titration with indicator added to see how much acid reacts completely with alkali.
Run volume of acid into solution of alkali again, but without indicator.
Crystallise + dry crystals of salt from reaction mixture.

Question 12

What colour are acids and alkalis on the Ph scale?

Answer 12

Acid=red,orange.

Alkali=blue,purple.

Question 13

What do all alkalis form?

Answer 13

Aqueous hydroxide ions.

Question 14

What is the difference between acids that are dilute solutions and concentrated solution ones?

Answer 14

6.0mol/dm3 of hydrochloric acid, relatively concentrated + labelled as corrosive. Whereas acidic solution diluted by adding water; gives solution of 0.10mol/dm3 of hydrochloric acid + labelled as irritant.

Question 15

What is the difference between a carboxylic (ethanoic) acid and hydrochloric acid of same concentration?

Answer 15

Carboxylic acids called weak acids, Hydrochloric acid called a strong acid. Weak acids not harmful when dilute nor harmful when concentrated.

Question 16

What happens if potassium is reacted with dilute acid?

Answer 16

It would explode.

Question 17

What happens if you react sodium or lithium with dilute acid?

Answer 17

They would explode.

Question 18

What would happen if you react calcium, magnesium, aluminium, zinc or iron with dilute acid?

Answer 18

Fizz, giving off hydrogen gas, and form a salt.

Question 19

What would happen if you react tin or lead with dilute acid?

Answer 19

It would react slowly with warm acid.

Question 20

What would happen if you try and react copper, silver or gold with dilute acid?

Answer 20

No reaction.