C3.4.1 Analysing substances

Question 1

What metal ion is present if a crimson flame is produced?

Answer 1

Lithium

Question 2

What metal ion is present if a yellow flame is produced?

Answer 2

Sodium

Question 3

What metal ion is present if a lilac flame is produced?

Answer 3

Potassium

Question 4

What metal ion is present if a brick-red flame is produced?

Answer 4

Calcium

Question 5

What metal ion is present if a green flame is produced?

Answer 5

Barium

Question 6

What ion is present if a green precipitate is formed when sodium hydroxide solution is added?

Answer 6

Iron (II)

Question 7

What ion is present if a red/brown precipitate is formed when sodium hydroxide solution is added?

Answer 7

Iron (III)

Question 8

What ion is present if a blue precipitate is formed when sodium hydroxide solution is added?

Answer 8

Copper

Question 9

What should you do if no precipitate is formed or a white precipitate is formed that doesn’t dissolve in excess sodium hydroxide?

Answer 9

Flame test

Question 10

What ion is present if a white precipitate is formed when sodium hydroxide solution is added that dissolves in excess NaOH?

Answer 10

Aluminum

Question 11

What ion is present if the gas that is given off when hydrochloric acid is added turns lime water cloudy?

Answer 11

Carbonate

Question 12

What ion is present if a white precipitate is formed when nitric acid and silver nitrate are added?

Answer 12

Chloride

Question 13

What ion is present if a cream precipitate is formed when nitric acid and silver nitrate are added?

Answer 13

Bromide

Question 14

What ion is present if a yellow precipitate is formed when nitric acid and silver nitrate are added?

Answer 14

Iodide

Question 15

What ion is present if a white precipitate is formed when hydrochloric acid and barium chloride are added?

Answer 15

Sulphate

Question 16

How do you work out the volumes of acids and alkali needed to react together to produce a neutral solution.

Answer 16

Titration and a suitable indicator.

Question 17

What can you do if you know the concentration of one of the reactants?

Answer 17

Calculate the concentration of the other reactant using the results from titration.

Question 18

How do you work out the concentration of a reactant with the results from a titration?

Answer 18

Convert volumes to dm3

Determine the number of moles of the reactant you know the concentration of.

Work out the number of moles of the other reactant using the balanced equation

Calculate the concentration of the reactant.