C4a-Chemical Changes: Reactivity and acids

Question 1

What is the reactivity series in order from most to least reactive?

Answer 1

• Potassium
• Sodium
• Lithium
• Calcium
• Magnesium
• Aluminium
• Carbon
• Zinc
• Iron
• Tin
• Lead
• Hydrogen
• Copper
• Silver
• Gold
• Platinum

Question 2

When metals react with water or dilute acids what is given off?

Answer 2

Hydrogen gas

Question 3

What is oxidation and reduction in terms of electrons?

Answer 3

Oxidation is loss
Reduction is gain

Question 4

1)What does metal + acid produce?
2)What does metal + water produce?
3)What does an acid + a base produce?
4)What does an acid + alkali produce?
5)What does an acid + metal carbonate produce?

Answer 4

1)Salt + hydrogen
2)Metal hydroxide + hydrogen
3)Salt + water
4)Salt + water
5)Salt + water + carbon dioxide

Question 5

How can metal be extracted from their oxides?

Answer 5

• By adding carbon to form carbon dioxide + metal
• By adding hydrogen to form water + metal

Question 6

What are some common charges on ions?

Answer 6

NH₄⁻, NO₃⁻, SO₄²⁻, CO₃²⁻

Question 7

What ions form an acid when added to water?

Answer 7

H⁺

Question 8

What ions form an alkali when added to water?

Answer 8

OH⁻

Question 9

What are bases?

Answer 9

Substances that will neutralise acids

Question 10

In the pH scale what is an acid and what is an alkali?

Answer 10

acid-ph 1-6.9
alkali-ph 7.1-14

Question 11

Give 3 examples of indicators

Answer 11

• Liquid indicaters such as universal indicator
• Litmus paper
• Digital indicators

Question 12

What is the main difference between strong and weak acids?

Answer 12

Strong acids ionise completely in solutions while weak acids only partially ionise in solutions