Analysis Substances

Question 1

Method for Flame test

metal ion test

Answer 1

Use a clean nichrome wire

Clean with acid

heat a salt in a blue flame an observe a colour flame.

Question 2

Flame test colour for Lithium (Li+)

Answer 2

crimson flame

Question 3

Flame test colour for Sodium (Na+)

Answer 3

yellow flame

Question 4

Flame test colour for Potassium (K+)

Answer 4

lilac flame

Question 5

Flame test colour for Calcium (Ca2+)

Answer 5

red flame

Question 6

Flame test colour for Barium (Ba2+)

Answer 6

green flame.

Question 7

Ion with a flame colour a crimson flame

Answer 7

Lithium (Li+)

Question 8

Ion with a flame colour a yellow flame

Answer 8

Sodium (Na+)

Question 9

Ion with a flame colour a lilac flame

Answer 9

Potassium (K+)

Question 10

Ion with a flame colour a red flame

Answer 10

Calcium (Ca2+)

Question 11

Ion with a flame colour a green flame.

Answer 11

Barium (Ba2+)

Question 12

Describe a solution test for determining Metal ions

Answer 12

Add sodium hydroxide solution slowly at first then excess to a dissolved solutions of a salt (ionic compounds).

Colour of precipitate and dissolving determine the ion.

Question 13

Observation when sodium hydroxide solution is added to a solution containing aluminium ions

Answer 13

a white precipitate which will dissolve on excess.

Question 14

Observation when sodium hydroxide solution is added to a solution containing Calcium ions

Answer 14

white precipitate.

Question 15

Observation when sodium hydroxide solution is added to a solution containing Magnesium ions

Answer 15

a white precipitate.

Question 16

Observation when sodium hydroxide solution is added to a solution containing Copper(II) ions

Answer 16

a blue precipitate.

Question 17

Observation when sodium hydroxide solution is added to a solution containing Iron(II) (Fe2+) ions

Answer 17

a green precipitate.

Question 18

Observation when sodium hydroxide solution is added to a solution containing Iron(III) (Fe3+) ions

Answer 18

a brown precipitate

Question 19

Name and formula of ion when a white precipitate is formed and dissolves when excess sodium hydroxide is added to a solution.

Answer 19

aluminium ions (Al3+)

Question 20

Name and formula of ion when a white precipitate is formed when sodium hydroxide is added to a solution

Answer 20

Calcium ions (Ca2+) Or Magnesium ions (Mg2+)

Question 21

Name and formula of ion when a Blue precipitate is formed when sodium hydroxide is added to a solution

Answer 21

Copper(II) ions (Cu2+)

Question 22

Name and formula of ion when a green precipitate is formed when sodium hydroxide is added to a solution

Answer 22

Iron(II) (Fe2+) ions

Question 23

Name and formula of ion when a brown precipitate is formed when sodium hydroxide is added to a solution

Answer 23

Iron(III) (Fe3+) ions

Question 24

Test for carbonate ions?

Answer 24

Add acid

see fizzing

Question 25

Name of the ion in a solution if acid is added and fizzing is seen?

Answer 25

carbonate ion

Question 26

Test for sulfate ions?

Answer 26

Add Barium chloride OR Barium nitrate white precipitate seen

Question 27

Test for Chloride ions

Answer 27

Add silver nitrate White precipitate seen

Question 28

Test for Bromide ions

Answer 28

Add silver nitrate Cream precipitate seen

Question 29

Test for Iodide ions

Answer 29

Add silver nitrate Yellow precipitate seen

Question 30

Name of the ion in a solution if barium nitrate is added and a white precipitate is seen?

Answer 30

Sulfate ion

Question 31

Name of the ion in a solution if barium chloride is added and a white precipitate is seen?

Answer 31

Sulfate ion

Question 32

Name of the ion in a solution if silver nitrate is added and a white precipitate is seen?

Answer 32

chloride ion

Question 33

Name of the ion in a solution if silver nitrate is added and a cream precipitate is seen?

Answer 33

Bromide ion

Question 34

Name of the ion in a solution if silver nitrate is added and a Yellow precipitate is seen?

Answer 34

iodide ion

Question 35

Method for titration

Answer 35

Volumes of acid and alkali can be measured using a technique called titration using a suitable indicator. Method to determine Concentration of Acid 1. Fill a Burette with a known concentration of alkali (e.g 0.1 mol /dm3). 2. Fill a conical flask with 25 cm3 of acid (unknown concnetration) using a pipette. 3. Add a few drops of an indicator to the conical flask. 4. Slowly add the alkali to the acid swirlling the solutions 5. Stop adding alkali to the acid when the indicator preminantly changes colour. 6. Record volume of alkali added. 7. Use results to calculate concentration of alkali. Visa versa for method to determine concnetration of alkali