chemical tests

Question 1

what do flame tests identify

Answer 1

metal ions

Question 2

in a flame test what colour does lithium go

Answer 2

red flame

Question 3

in a flame test what colour does sodium go

Answer 3

yellow flame

Question 4

in a flame test what colour does potassium go

Answer 4

lilac flame

Question 5

in a flame test what colour does calcium go

Answer 5

orange-red flame

Question 6

in a flame test what colour does copper go

Answer 6

blue-green

Question 7

how do you do a flame test

Answer 7

get a clean platinium wire loop by dipping it in diluted hydrochloric acid and holding it in the flame. Once you hold the loop in the flame and it burns without any colour you can dip it in the sample you want to test, then put it over the blue flame to see the colour.

Question 8

does the flame test test for cations or anions

Answer 8

cations

Question 9

what do some metals form with NaOH

Answer 9

coloured precipitate

Question 10

explain how you test for metal ions using sodium hudroxide (NaOH)

Answer 10

add a few drops of sodium hydroxide to the unknown compound in a test tube and if you get a colourd insoluble hydroxide you can tell what was in the compound

Question 11

what is the precipitate colour of copper(ii)

Answer 11

blue

Question 12

what is the precipitate colour of iron(ii)

Answer 12

sludgy green

Question 13

what is the precipitate colour of iron(iii)

Answer 13

red- brown

Question 14

what is the charge on OH

Answer 14

-

Question 15

how do you test for ammonia

Answer 15

use red litmus paper and if amonia is present it will turn blue

Question 16

how do you test for carbonates

Answer 16

add dilute hydrochloric acid to the test sample and if carbonated are present carbon dioxide will be released

Question 17

how do you test for sulfates

Answer 17

add dilute hydrochloric acid followed by barium chloride solution and a white precipitate should form for a postaive result

Question 18

how do you test for chloride, bromide or iodide ions (halides)

Answer 18

add dilute nitric acid followed by silver nitrate solution.

Question 19

what does a chloride ion give

Answer 19

white precipitate of silver chloride

Question 20

what does a bromide ion give

Answer 20

a cream precipitate of silver bromide

Question 21

what does a iodine ion give

Answer 21

yellow precipitate of silver choloride

Question 22

how do you test for chlorine

Answer 22

bleached damp blue litmus paper, turning it white

Question 23

how do you test for oxygen

Answer 23

re-lights a glowing splint

Question 24

how do you test for carbon dioxide

Answer 24

turns lime water cloudy

Question 25

how do you test for hydrogen

Answer 25

skueaky pop test

Question 26

how do you test for ammonia

Answer 26

turns damp red litmus paper blue

Question 27

how do you test for water

Answer 27

anhydrous copper (ii) sulfate and see if it turns blue

Question 28

how do tou test for alkenes

Answer 28

if you add an alkene to bromine water, they will stay orange