Chemical and Physical tests

Question 1

How do you carry out a flame test?

Answer 1

• dip the nichrome wire into hydrochloric acid to clean it
• put the nichrome wire into the sample solid/liquid
• place into blue roaring flame
• describe the colour

Question 2

in a flame test what do you see when lithium ions are present?

Answer 2

red

Question 3

in a flame test what do you see when sodium ions are present?

Answer 3

yellow

Question 4

in a flame test what do you see when potassium ions are present?

Answer 4

lilac

Question 5

in a flame test what do you see when calcium ions are present?

Answer 5

orange - red

Question 6

in a flame test what do you see when copper ions are present?

Answer 6

blue - green

Question 7

what is the test for hydrogen?

Answer 7

lit splint causes a squeaky pop if hydrogen is present

Question 8

what is the test for oxygen?

Answer 8

glowing splint relights if oxygen is present

Question 9

what is the test for carbon dioxide?

Answer 9

bubble through limewater - if present limewater goes milky white

Question 10

what is the test for ammonia (NH3)?

Answer 10

dam red litmus paper goes blue

Question 11

what is the test for chlorine?

Answer 11

damp limbs paper bleaches white

Question 12

how do you carry out the halide tests?

Answer 12

• add nitric acid to remove any carbonate ions

- add sliver nitrate and a precipitate will form

Question 13

in the halide tests what colour will the precipitate go if chloride ions are present?

Answer 13

white

Question 14

in the halide tests what colour will the precipitate go if bromide ions are present?

Answer 14

cream

Question 15

in the halide tests what colour will the precipitate go if iodide ions are present?

Answer 15

pale yellow

Question 16

how do you test for carbonate ions?

Answer 16

add hydrochloric acid and a gas will form
bubble the gas through limewater
a carbonate will produce limewater and CO2. It will go cloudy white.

Question 17

what is the chemical test for water?

Answer 17

add to anhydrous copper sulphate - will go blue

Question 18

what is the test for alkenes?

Answer 18

bromine water will go orange to colourless

Question 19

what is the physical test for water?

Answer 19

water freezes at 0 degrees.

water boils at 100 degrees

Question 20

how do you carry out the metal cation tests?

Answer 20

add sodium hydroxide

identify the precipitate

Question 21

in the metal cation tests what colour will the precipitate be if copper ions are present?

Answer 21

blue

Question 22

in the metal cation tests what colour will the precipitate be if iron (III) ions are present?

Answer 22

orange/brown

Question 23

in the metal cation tests what colour will the precipitate be if iron ions are present?

Answer 23

green

Question 24

what is the sulphate test?

Answer 24

• add barium chloride

- white precipitate of barium sulphate will form is sulphate ions present.

Question 25

what is the test for ammonium?

Answer 25

• add sodium hydroxide
• warm it
• test for ammonia
  damp red litmus goes blue