chemical and physical tests ✓

Question 1

how do you do a flame test ?

Answer 1

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

Question 2

what is the flame colour for lithium ions ?

Answer 2

bright red

Question 3

what is the flame colour for sodium ions ?

Answer 3

yellow/orange

Question 4

what is the flame colour for potassium ions ?

Answer 4

lilac

Question 5

what is the flame colour for calcium ions ?

Answer 5

orange/red

Question 6

what is the flame colour for copper ions ?

Answer 6

blue/green with white streaks

Question 7

what is the test for hydrogen gas (H2) ?

Answer 7

light splint into test tube creates a squeaky pop

Question 8

what is the test for oxygen gas (O2) ?

Answer 8

glowing splint into test tube will re-light

Question 9

what is the test for carbon dioxide gas (CO2) ?

Answer 9

bubbled through limewater the limewater will create a cloudy white precipitate

Question 10

what is the test for ammonia gas (NH3) ?

Answer 10

damp red litmus paper goes blue

Question 11

what is the test for chlorine gas (Cl2) ?

Answer 11

damp red or blue litmus paper will be bleached white

Question 12

how do you complete a halide test ?

Answer 12

• put solution in a test tube
• add nitric acid to get rid of the impurities (carbonate ions)
• add silver nitrate and the precipitate will form

Question 13

what is the colour for chloride ions in the halide test ?

Answer 13

white

Question 14

what is the colour for bromide ions in the halide test ?

Answer 14

cream

Question 15

what is the colour for iodide ions in the halide test ?

Answer 15

yellow

Question 16

what is the chemical test for water ?

Answer 16

anhydrous copper sulphate will go blue if liquid is water

Question 17

what is a physical test for water ?

Answer 17

water will boil at exactly 100°C

Question 18

what is a physical test for water ?

Answer 18

water will freeze at exactly 0°C

Question 19

what is the test for alkenes ?

Answer 19

bromine water goes from orange to colourless

Question 20

how do you do a metal cation test ?

Answer 20

• put solution in test tube
• add sodium hydroxide
• identify the coloured precipitate

Question 21

what colour do iron 2+ (Fe2+) ions go ?

Answer 21

makes a green precipitate

Question 22

what colour do iron 3+ (Fe3+) ions go ?

Answer 22

makes an orange/brown precipitate

Question 23

what colour do copper 2+ ions (Cu2+) go ?

Answer 23

makes a blue precipitate

Question 24

what is the test for ammonium (NH4+ ions) ?

Answer 24

• put solution in test tube
• adds sodium hydroxide
• warm it
• test for ammonia (damp red litmus paper goes blue)

Question 25

what is the test for a sulphate (SO4 2- ions) ?

Answer 25

• put solution in test tube
• add barium chloride
• white precipitate of barium sulphate forms

Question 26

what is the test for a carbonate ?

Answer 26

• add dilute hydrochloric acid to substance
• if carbonates are present carbon dioxide will be released
• do test for carbon dioxide (limewater)