Chemical Analysis

Question 1

Pure means

Answer 1

Only contains one type of element or compound

Question 2

Pure substances can

Answer 2

Melt and solidify at one temperature- melting point

Boil and condense at one temperature- boiling point

Question 3

Impure substance are

Answer 3

Mixtures

Question 4

Impure substances dont

Answer 4

Melt and boil at one temperature

They change state over a range of temperatures

Question 5

Formulations are

Answer 5

Mixtures that have been carefully designed to have specific properties
Complex mixtures in which each chemical has a particular purpose
The components are carefully controlled

Question 6

Phases of chromatography

Answer 6

Stationary phase does not move

Mobile phase does move

Question 7

Stationary phase is

Answer 7

Absorbent paper

Oh

Question 8

Mobile phase is the

Answer 8

Solvent which is usually the water

Question 9

Chromatography separates

Answer 9

Mixtures into the constituent components

Question 10

R value =

Answer 10

Distance moved by substance /

Distance moved by solvent

Question 11

Properties of hydrogen

Answer 11

Colourless gas combines violently with oxygen when ignited

Question 12

hydrogen test

Answer 12

When mixed with air burns with the squeaky pop

Question 13

properties of chlorine

Answer 13

A greens Poisonous gas that bleaches dies

Question 14

Chlorine test

Answer 14

Turns damp litmus paper white

Question 15

Properties of oxygen

Answer 15

Colourless gas that helps fuels burn more readily than in air

Question 16

oxygen test

Answer 16

Relights a glowing splint

Question 17

Carbon dioxide properties

Answer 17

Colourless gas

Question 18

Carbon dioxide test

Answer 18

When bubbles through limewater turns the lime water cloudy

Question 19

Standard laboratory equipment can be used to

Answer 19

Detect and identify elements and compounds

However new highly accurate instrument can analyse and identify substances more effectively

Question 20

Flame emission spectroscopy

Answer 20

Very useful instrumental method
Used to analyse solutions that contain metal ions
A sample Is put in a flame and the light is passed through a spectroscope
This produces a line spectrum

Question 21

A line spectrum can be used to

Answer 21

Identify the metal ion

Measure the concentration of the ion

Question 22

Flame tests identify

Answer 22

Metal ions- cations

Question 23

Copper flame

Answer 23

Green

Question 24

Calcium flame

Answer 24

Brick red

Question 25

Lithium flame

Answer 25

Crimson

Question 26

Pottasium fkame

Answer 26

Lilac

Question 27

Sodium flame

Answer 27

Yellow

Question 28

If a sample contains a mixture of ions(flame)

Answer 28

The coulour of some ions can be masked Eg Soloution with sodium and potassium Pale lilac is hard to see over the yellow

Question 29

Carbonates react with dilute acids to form

Answer 29

Carbon dioxide gas And salt and water

Question 30

Calcium carbonate + hydrochloric acid —>

Answer 30

Calcium chloride + Carbon dioxide + Water

Question 31

Most metal carbonates are

Answer 31

Insoluble

Question 32

Sodium carbonate and pittssium carbonate are

Answer 32

Soluble and dissolve in water to form solutions that contain carbonate ions

Question 33

Some metal ions form

Answer 33

Precipitates

Question 34

Precipitates are

Answer 34

Insoluble solids that come out of soilution when sodium hydroxide is added

Question 35

Aluminium precipitates

Answer 35

Aluminium hydroxide White Dissolved in excess

Question 36

Calcium precipitates

Answer 36

Calcium hydroxide White

Question 37

Magnesium precipitates

Answer 37

Magnesium hydroxide White

Question 38

Copper(II) precipitates

Answer 38

Copper(II) hydroxide Blue

Question 39

Irom(II) precipitates

Answer 39

Iron(II) hydroxide Green

Question 40

Iron(III) precipitates

Answer 40

Iron(III) hydroxide Brown

Question 41

If dilutes hydrochloric acid and barium chloride or added to the solution containing sulphate ions

Answer 41

A white precipitate of barium sulphate is produced

Question 42

Halide test

Answer 42

Add nitric acid Add silver nitrate Silver halide precipitates form

Question 43

Silver chloride precipitates

Answer 43

White

Question 44

Silver bromide precipitates

Answer 44

Cream

Question 45

Silver iodide precipitates

Answer 45

Yellow