Acids and Alkalis - Chemical Changes

Question 1

What is a base?

Answer 1

Insoluble substance after ph 7

Question 2

Name the 2 types of bases

Answer 2

• Alkalis - soluble in water
• Insoluble bases - Insoluble in water

Question 3

What does it mean if a molecule has hydroxide?

Answer 3

It’s an alkali

Question 4

What happens when an alkali is dissolved in water?

Answer 4

Alkalis ionise into metal ions and hydroxide ions

Question 5

What is the word equation for neutralisation?

Answer 5

Acid + Alkali –> Soluble salt + Water

Question 6

What is the ionic symbol equation for neutralisation?

Answer 6

H⁺+ OH⁻ –> H₂O

Question 7

What ion makes acids acidic?

Answer 7

H⁺

Question 8

Hydrochloric acid

Answer 8

HCl

Question 9

Nitric Acid

Answer 9

HNO₃

Question 10

Sulfuric Acid

Answer 10

H₂SO₄

Question 11

What happens when acids dissolve in water?

Answer 11

They ionise to non-metals ions and hydrogen ions

Question 12

Why is excess base added to an acid?

Answer 12

So all the acid reacts

Question 13

SOLUBLE OR INSOLUBLE

Metal Oxide

Answer 13

Insoluble base

Question 14

SOLUBLE OR INSOLUBLE

Metal Carbonate

Answer 14

Insoluble

Question 15

Write the word equation for an acid and carbonate reaction

Answer 15

carbonate + acid –> Salt + Water + Carbon dioxidet

Question 16

What is a salt?

Answer 16

Non metal + Metal

Question 17

Write the word equation for an acid and metal

Answer 17

Metal + Acid –> Hydrogen + Salt

Question 18

Why is HCl a strong acid?

Answer 18

Because every molecule fully ionises in an aqueous solution so they release H⁺ ions. Therefore, a high concentration of H⁺ means a lower pH (more acidic).

Question 19

What makes an acid weak?

Answer 19

When ions partially ionise in an aqueous solution, the concentration of H⁺ ions are lower, so a higher pH (less acidic) AND if the equation has a reversible sign

Question 20

Name 3 weak acids

Answer 20

Citric acid, ethanoic acid, Carbonic acid