Acids & Bases (Chemical Changes partial)

Question 1

How does diluting an acid with water affect its pH?

Answer 1

The pH increases towards 7.

Question 2

What is made when an acid reacts with a base?

Answer 2

A salt and water.

Question 3

Is neutralisation endothermic or exothermic?

Answer 3

Exothermic.

Question 4

What ion is formed when alkalis dissolve in water?

Answer 4

OH⁻

Question 5

What ion makes substances acidic?

Answer 5

H⁺

Question 6

How are alkalis different to bases?

Answer 6

Alkalis dissolve in water but bases don’t.

Question 7

Hydrochloric acid with a pH of 1 is how many times stronger than ethanoic acid with a pH of 4?

Answer 7

1000

Question 8

What does the pH of a solution measure?

Answer 8

Hydrogen ion (H⁺) concentration.

Question 9

Many foods and drinks contain acids. However, in the classroom or laboratory people wear safety goggles when they use an acid. Explain why.

Answer 9

The acids in the classroom or laboratory are more concentrated than the acids in foods and drinks.

Question 10

What is observed when magnesium reacts with an acid?

Answer 10

Fizzing/bubbles.

Question 11

Ammonia + acid ->

Answer 11

Ammonium salt

Question 12

Ammonia + hydrochloric acid ->

Answer 12

Ammonium chloride

Question 13

Carbonate ion

Answer 13

CO₃^2-

Question 14

Ammonium ion

Answer 14

NH⁴⁺

Question 15

Phosphoric acid

Answer 15

H₃PO₄

Question 16

Phosphate ion

Answer 16

PO₄^3-