C12 Chemical analysis

Question 1

what’s the colour of the flame when lithium is put in it (flame test)

Answer 1

crimson

Question 2

what’s the colour of the flame when sodium is put in it (flame test)

Answer 2

yellow

Question 3

what’s the colour of the flame when potassium is put in it (flame test)

Answer 3

lilac

Question 4

what’s the colour of the flame when calcium is put in it (flame test)

Answer 4

orange-red

Question 5

what’s the colour of the flame when copper is put in it (flame test)

Answer 5

green

Question 6

what do you use for metal cation test to find out what metal you have in an unknown solution

Answer 6

sodium hydroxide

Question 7

in metal cation tests with sodium hydroxide how do you know if you have copper ions

Answer 7

a blue precipitate appears

Question 8

in metal cation tests with sodium hydroxide how do you know if you have iron(II) ions

Answer 8

a green precipitate appears

Question 9

in metal cation tests with sodium hydroxide how do you know if you have iron(III) ions

Answer 9

a brown precipitate appears

Question 10

in metal cation tests with sodium hydroxide how do you know if you have magnesium ions

Answer 10

a white precipitate appears and is insoluble in excess sodium hydroxide

Question 11

in metal cation tests with sodium hydroxide how do you know if you have aluminium ions

Answer 11

a white precipitate forms and dissolved in excess sodium hydroxide

Question 12

in metal cation tests with sodium hydroxide how do you know if you have calcium ions

Answer 12

a white precipitate forms and is insoluble in excess sodium hydroxide

Question 13

what’s the test for sulfates

Answer 13

add dilute hydrochloric acid
add barium chloride solution
a white precipitate means sulfate ions are present

Question 14

what’s the test for halides

Answer 14

add nitric acid
add silver nitrate solution
if a precipitate forms halide ions are present

Question 15

what colour does each halide ion form in the test for halides

Answer 15

iodine- yellow
bromide- cream
chloride- white

Question 16

what’s the test for carbonates

Answer 16

add a dilute acid
if it fizzes and produces co2 it’s a carbonate

Question 17

test for hydrogen

Answer 17

if a flame is put in it it burns with a squeaky pop

Question 18

what’s the test for oxygen

Answer 18

relights a glowing splint

Question 19

what’s the test for chloride gas

Answer 19

a damp piece of blue litmus paper will turn white

Question 20

what’s the test for carbon dioxide

Answer 20

turn limewater milky white