Chemical tests

Question 1

How do you test for hydrogen?

Answer 1

collect gas and place lit splint near, Squeaky pop test

Question 2

How do you test for oxygen?

Answer 2

collect gas and it will relight a smoldering splint

Question 3

How do you test for carbon dioxide?

Answer 3

limewater goes cloudy or extinguishes a lit splint (usually use limewater test as is unique)

Question 4

How do you test for chlorine?

Answer 4

damp blue litmus paper bleaches

Question 5

How do you test for a double carbon bond?

Answer 5

Bromine water turns colourless

Question 6

How do you carry out a flame test?

Answer 6

1. Dip a clean wire loop into a solid sample of the compound being tested. 2. Put the loop into the edge of the blue flame from a Bunsen burner. 3. Observe and record the flame colour produced.

Question 7

What is the flame colour of potassium?

Answer 7

lilac

Question 8

What is the flame colour of strontium?

Answer 8

red

Question 9

What is the flame colour of calcium?

Answer 9

orange-red

Question 10

What is the flame colour of sodium?

Answer 10

yellow

Question 11

What is the flame colour of barium?

Answer 11

apple green

Question 12

What is the flame colour of copper?

Answer 12

blue-green

Question 13

What is the flame colour of magnesium?

Answer 13

white

Question 14

What is the flame colour of aluminium?

Answer 14

grey-white

Question 15

What colour precipitate do chloride ions form?

Answer 15

white

Question 16

What colour precipitate do bromide ions form?

Answer 16

cream

Question 17

What colour precipitate do iodide ions form?

Answer 17

yellow

Question 18

How do you carry out the test for sulfate ions?

Answer 18

1. Add dilute hydrochloric acid to sample. 2. Add barium chloride solution. 3. If sulfate ions are present we will see a white precipitate.

Question 19

How do you carry out the test for halide ions?

Answer 19

1. Add dilute nitric acid to the sample. 2. Add dilute silver nitrate solution. 3. Halide ions produce a precipitate of the silver halide.

Question 20

How do you carry out the test for carbonate ions?

Answer 20

1. Add dilute acid to the sample. 2. The acid will react to produce carbon dioxide gas, you will see effervescence. 3. Bubble the gas throughout lime water which will turn cloudy.

Question 21

Sodium hydroxide test for aluminium?

Answer 21

white precipitate, dissolves in excess

Question 22

Sodium hydroxide test for magnesium?

Answer 22

white precipitate

Question 23

Sodium hydroxide test for calcium?

Answer 23

white precipitate

Question 24

Sodium hydroxide test for copper II?

Answer 24

light blue precipitate

Question 25

Sodium hydroxide test for iron II?

Answer 25

light green to brown precipitate

Question 26

Sodium hydroxide test for iron III?

Answer 26

reddish-brown precipitate

Question 27

How do you determine a pure substance?

Answer 27

pure substances have sharp melting points, mixtures melt over a range of temperatures.

Question 28

What is a formulation?

Answer 28

a useful mixture, with exact measurements.

Question 29

Name an accurate method of analysing the substances of a mixture?

Answer 29

flame emission spectroscopy

Question 30

What is meant by pure?

Answer 30

a substance that consists of only one type of element or only one compound.