qualitative analysis

Question 1

flame test lithium

Answer 1

red

Question 2

flame test sodium

Answer 2

yellow

Question 3

flame test potassium

Answer 3

lilac

Question 4

flame test calcium

Answer 4

orange-red

Question 5

flame test copper

Answer 5

blue-green

Question 6

test for carbon dioxide

Answer 6

bubbling through limewater (turns cloudy)

Question 7

why must the test for any ion be unique?

Answer 7

so you can determine which ion is present without confusion, if the test is not specific, another test would be required to determine the ion

Question 8

carbonate ion test

Answer 8

two centimetres of the solution being tested
add a few drops of dilute hydrochloric acid

Question 9

testing for sulphate ions

Answer 9

two centimetres of the solution being tested
add a few drops of dilute hydrochloric acid and shake
add a few drops of barium chloride

Question 10

halide ion test

Answer 10

two centimetres of the solution being tested
add a few drops of dilute nitric acid and shake
add a few drops of silver nitrate

Question 11

carbonate ion positive test

Answer 11

bubbling occurs

Question 12

sulphate ion positive test

Answer 12

white precipitate forms

Question 13

chloride ion halide test positive result

Answer 13

white precipitate forms

Question 14

bromide ion halide test positive result

Answer 14

cream precipitate forms

Question 15

iodide ion halide test positive result

Answer 15

yellow precipitate forms

Question 16

cation precipitate test

Answer 16

two centimetres of the solution being tested
add a few drops of sodium hydroxide and shake
observe precipitate formed (if white complete next step)
fill the tube about halfway with sodium hydroxide

Question 17

copper precipitate test

Answer 17

blue

Question 18

iron (II) precipitate test

Answer 18

green

Question 19

iron (III) precipitate test

Answer 19

brown

Question 20

calcium precipitate test

Answer 20

white (stays the same/remains cloudy when excess sodium hydroxide is added)

Question 21

aluminium precipitate test

Answer 21

white (turns colourless when excess sodium hydroxide is added)

Question 22

ammonium ion test

Answer 22

two centimetres of the solution being tested
add a few drops of dilute sodium hydroxide
warm the mixture
hold damp red litmus paper over the test tube

Question 23

ammonium ion positive result

Answer 23

litmus paper turns blue

Question 24

chlorine gas test

Answer 24

hold damp blue litmus paper over the mouth of the test tube which is filled with the gas being tested

Question 25

chlorine gas positive result

Answer 25

litmus paper turns red

Question 26

ammonia gas test

Answer 26

hold damp red litmus paper over the mouth of the test tube which is filled with the gas being tested

Question 27

ammonia gas positive result

Answer 27

red litmus paper turns blue

Question 28

oxygen gas test

Answer 28

test tube filled with the gas being tested get a glowing split and hold it inside the test tube

Question 29

oxygen gas positive result

Answer 29

the glowing splint combusts and relights

Question 30

hydrogen gas test

Answer 30

test tube filled with the gas being tested hold a lit splint over the mouth of the test tube

Question 31

hydrogen gas positive test

Answer 31

squeaky pop noise

Question 32

test for water

Answer 32

using anhydrous copper (II) sulphate which is originally white solid add the substance being tested for water

Question 33

water positive test result

Answer 33

turns blue

Question 34

test for water purity

Answer 34

pure water should boil at 100 degrees

Question 35

water impurity positive result

Answer 35

water boils at a temperature higher or lower than 100 degrees

Question 36

what do instrumental methods of analysis improve?

Answer 36

sensitivity, accuracy and speed of tests

Question 37

which methods improve speed, accuracy and sensitivity of tests?

Answer 37

instrumental methods

Question 38

carbonate ionic equation

Answer 38

CO3^2- (aq) + 2H^+ (aq) --> CO2 (g) + H2O (l)

Question 39

sulphate ionic equation

Answer 39

Ba^2+ (aq) + SO4^2- (aq) --> BaSO4 (s)

Question 40

halide ionic equation

Answer 40

Ag+ (aq) + X- (aq) --> AgX (s) where X = Cl^-, Br^- or I^-

Question 41

uses of a flame photometer

Answer 41

measures light intensity so you can find the concentration of ions using a calibration curve) in a dilute solution and make an emission spectra also identify metal ions by comparing the data with reference data