Chemistry of acids

Question 1

Define an acid and give the three main ones

Answer 1

A substance that donates H+ ions in a solution

HCl, H2S04, HNO3

Question 2

Define a base and give an example

Answer 2

A substance that neutralises an acid

CuO

Question 3

Define an alkali and name the two main types

Answer 3

A soluble base that donates hydroxide ions (OH-) in a solution
NaOH, KOH

Question 4

What is meant by a neutralisation reaction

Answer 4

When an acid and a base react to form a neutral solution

Question 5

acid+metal makes

Answer 5

Salt+hydrogen

Question 6

acid+base makes

Answer 6

salt+water (neutralisation)

Question 7

acid+alkali makes

Answer 7

Salt+water (neutralisation)

Question 8

acid+metal carbonate makes

Answer 8

Salt+Water+carbon dioxide (neutralisation)

Question 9

What is one mole equal to

Answer 9

Arogadro’s constant or 6.02x10^23 atoms

Question 10

How do you calculate the mole value of a substance

Answer 10

moles= mass (g) ÷ Mr value

Question 11

How would you calculate mass with unknown values

Answer 11

Draw out table fo the two substances with moles, mass and Mr then work it out from there

Question 12

What is the range of the pH scale

Answer 12

0-14

Question 13

What does the pH of 7 mean

Answer 13

Neutral substance

Question 14

What does a pH of less than 7 mean

Answer 14

Acidic substance

Question 15

Wghat does the pH of more than 7 mean

Answer 15

Alkaline substance

Question 16

Recite the seven steps of a titration experiment

Answer 16

1. Fill biurette with hydrochloric acid.
2. add unknown alkali to conical flask.
3. add universal indicator.
4. Begin to add small amounts of the acid into the flask. 5. Continue until the indicator changes colour.
5. Note amount of acid used.
6. Repeat three times.

Question 17

How would you calculate the concentration of a solution from a titration experiment

Answer 17

concentration (mol/dm^3)+ moles ÷ volume (dm^3)

Question 18

Name the two units for concentration

Answer 18

1. mol/dm^3

2. g/dm^3

Question 19

How would you convert cm^3 to dm^3

Answer 19

÷1000

Question 20

How would you convert dm^3 to cm^3

Answer 20

x1000

Question 21

What is acid dissociation

Answer 21

When an acid is added to water it dissociates and releases H+ ions

Question 22

Define a strong acid in terms of dissociation and give the three main strong acids

Answer 22

completely dissociates in water

HCl, HNO3, H2S04

Question 23

Define a weak acid and give an example of a reaction

Answer 23

partially dissociates in water

CH3COOH ⇌ CH3COO- + H+

Question 24

Define concentration

Answer 24

The amount of water or acid particles in a given volume

Question 25

What is difference between two pH values

Answer 25

10x

Question 26

Outline the test for sulphate ions

Answer 26

1. To solution add hydrochloric acid to get rid of carbon compounds 2. Add barium chloride 3. If white precipitate forms then sulphate is present

Question 27

Outline the test for carbonate ions

Answer 27

1.C02 Bubbles are produced when hydrochloric acid is added

Question 28

What are the colours that universal indicator goes fro acids and alkalines

Answer 28

``` Acids = red Alkalines = purple ```

Question 29

What is aqeous neutralisation

Answer 29

When hydrogen ion react with hydroxide ions to form water