Acids and Bases

Question 1

Arrhenius definition of an acid

Answer 1

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

Question 2

Arrhenius definition of A base

Answer 2

Is a substance that dissociates in water to form OH- ions

Question 3

Arrhenius definition of A strong acid

Answer 3

A substance that almost completely dissociates in water to give H ions

Question 4

Arrhenius definition of A weak acid

Answer 4

A substance that only slightly dissociates in water to give H ions

Question 5

Arrhenius definition of a strong base

Answer 5

A substance that almost completely dissociates in water to form OH ions

Question 6

Arrhenius definition of A weak base

Answer 6

Substance that only slightly dissociates in water to give hydroxide ions

Question 7

Brønsted-Lowry definition of an acid

Answer 7

An acid is a proton donor

Question 8

Brønsted-Lowry definition of A base

Answer 8

A proton acceptor

Question 9

Brønsted-Lowry definition of Strong acid

Answer 9

A good proton donor

Question 10

Brønsted-Lowry definition of A weak acid

Answer 10

Poor proton donor

Question 11

Brønsted-Lowry definition of A strong base

Answer 11

Good proton acceptor

Question 12

Brønsted-Lowry definition of A weak base

Answer 12

Poor proton acceptor

Question 13

What is an alkali

Answer 13

A base that is solvable in water

Question 14

What is a proton otherwise known as

Answer 14

A H+ ion

Question 15

What does the Equilibrium symbol mean?

Answer 15

Reaction is going in both directions Ie you cannot know moles from the balanced equation

Question 16

What is a monoprotic/basic acid

Answer 16

An acid that dissociates to give one proton

Question 17

What is a diprotic/basic acids

Answer 17

An acid that dissociates to give 2 protons

Question 18

Give an example of a monoprotic balanced equation

Answer 18

HCl=H+ + Cl-

Question 19

Give an example of a diprotic balanced equation

Answer 19

H2SO4 + H2O = H3O+ + HSO4-

Question 20

What are the limitations to Arrhenius’ theory of acids and bases

Answer 20

H+ ions do not exist on their own in solution. They form the H3O+ ion

Arrhenius’ definitions are restricted to aqueous solutions. Water is not the only solvent

NH3 cannot be considered a base

Question 21

Compare Arrhenius and Brønsted-Lowry

Answer 21

Arrhenius:
-Theory is restricted to only aqueous solutions
-bases produce OH- ions in water
- does not take hydronium ion formation into account

Brønsted-Lowry:
-can involve reactions that occur in the gaseous state
- not all bases produces OH- ions for example NH3
- takes hydronium ion formation into account

Question 22

What does amphoteric mean

Answer 22

Behave as either an acid or a base

Question 23

Under what circumstances do acids become conjugate bases?

Answer 23

When it donates a proton

Question 24

Under what circumstances does a base become a conjugate acid

Answer 24

Accepts a proton

Question 25

What is a conjugate base pair

Answer 25

Any pair consisting of an acid and a base that differ by a proton

Question 26

How to find the conjugate base

Answer 26

Decrees no of H by 1 Decrease charge by 1

Question 27

How to find conjugate acid

Answer 27

Increase no of H by 1 Increase charge by 1

Question 28

What does a strong acid have

Answer 28

Weak conjugate base

Question 29

What does a weak acid have

Answer 29

A strong conjugate base

Question 30

Why do strong acids have weak conjugate bases

Answer 30

Strong acids fully disassociate In water and it is unlikely for a reaction to go in the reverse direction thus it is a weak base

Question 31

Write a balanced equation to show how acid dissociates in water

Answer 31

Acid + water = weak base + acid

Question 32

Neutralisation

Answer 32

A reaction between an acid and a base, forming a salt and a water

Question 33

Eg of a neutralisation balanced equation

Answer 33

NaOH+HCl ->NaCl + H2O

Question 34

What is a salt

Answer 34

A substances formed when the H+ ion from an acid is replaced by a metal or ammonium ion

Question 35

Give an example of a balanced equation of a salt

Answer 35

NaOH + HCl -> NaCl + H2O

Question 36

Give 2 examples of a neutralisation reaction

Answer 36

Agriculture- if soil is too acidic lime is spread on soil to increase pH. Some crops do not grow well in acidic soil CaO + H2O -> Ca(OH)2 Environmental- In areas where acid rain is a problem limestone is added to lakes to increase pH H2SO4 + CaCO3 -> CaSO4 + H2O + CO2