Acids and Bases

Question 1

What colour do acids turn blue litmus paper to?

Answer 1

Red

Question 2

Name some common household acids

Answer 2

Lactic acid, Citric acid, ethanoic acid, stearic acid, acetylsalicylic

Question 3

Name some common laboratory acids

Answer 3

Hydrochloric acid, Nitric acid, sulphuric acid, phosphoric acid

Question 4

What was Arrhenius’ definition of an acid/Theory

Answer 4

An acid is a substance that dissociates in water to form H+ ions.

Question 5

What is a monobasic acid, and give an example

Answer 5

Acids that donate one H⁺ ion, eg HCL and HNO3

HNO3 ⟶ H⁺ + NO3

Question 6

What is a dibasic acid, and name an example

Answer 6

A dibasic acid donates two H⁺ ions, e.g H₂SO₄

H₂SO₄⟶ 2H⁺ + SO₄²

Question 7

What is a tribasic acid, and give an example

Answer 7

A tribasic acid donate three H⁺ ions, e.g H₃PO₄

H₃PO₄ ⟶ 3H⁺ + PO₄³

Question 8

Define a strong acid, using Arrhenius theory

Answer 8

It is one that fully dissociates in water, e.g HCL, H₂SO₄, HNO₃
HCL + H₂O ⟶ H₃O⁺ + Cl⁻

Question 9

Define a weak acid, using Arrhenius Theory

Answer 9

A weak acid is one that only slightly dissociates in water to form hydrogen ions

CH₃COOH + H₂O ↛ H₃O⁺ + CH₃COO⁻

Question 10

What colour do bases turn red litmus paper

Answer 10

Blue

Question 11

General info

Answer 11

Bases have soapy feel

They are used as degreasers in household detergents

Act by converting the oil into soap, which washes away more easily

Question 12

Name some common household bases

Answer 12

Magnesium hydroxide, Ammonia, Sodium hydroxide, Sodium hydrogen carbonate, calcium hydroxide

Question 13

Name some common laboratory bases

Answer 13

Sodium hydroxide- NaOH
Calcium hydroxide- Ca(OH)₂
Ammonia- NH₃
Sodium carbonate- Na₂CO₃

Question 14

What is Arrhenius Theory of bases

Answer 14

It is defined as a substance that dissociates in water to produce OH⁻ ions, e.g NaOH
NaOH ⟶ Na⁺ + OH⁻

Question 15

What is a strong base in relation to Arrhenius’ Theory

Answer 15

It is a base that fully dissociates in water, e.g NaOH

Question 16

What is a weak base in relation to Arrhenius’ Theory

Answer 16

It is a base that does not fully dissociate in water, e.g Mg(OH)₂

Question 17

What are the Limitations of Arrhenius’ Theory

Answer 17

1. The acids must be in aqueous solutions(water)
2. Not all acid-base reactions are in a solution, e.g ammonia gas and hydrogen chloride gas produce ammonium chloride.
3. According to Arrhenius, the salt produced should not be acidic or basic( not always case)
4. Not all bases contain OH example NH₃

Question 18

What is an acid definition in relation to the Bronsted-Lowry Theory

Answer 18

An acid is a substance that donates protons(hydrogen ions)

Question 19

What is a base definition, in relation to the Bronsted-Lowry Theory

Answer 19

A base is a substance that accepts protons

Question 20

Read up on how it donate and accepts

Question 21

What is Amphoteric

Answer 21

Any substance able to act as both an acid and a base

Question 22

What is Neutralisation

Answer 22

Neutralisation is the reaction between an acid and a base to form salt and water

Question 23

Everyday Neutralisation

Answer 23

Indigestion remedies are bases that neutralise excess stomach acid.

Toothpaste is a base that neutralises acid in the mouth

Lime is a base that neutralises acid in soil

Wasp stings are basic

Nettle, bee and ant stings are acidic

Question 24

What is a conjugate base

Answer 24

It is an acid after it donates a proton

Question 25

What is a conjugate acid

Answer 25

It is a base after it accepts a proton