Paper 2- Unit 8 Chemical tests (Triple Only) Flashcards
Which metal gives a green flame?
Copper Cu 2+
Which metal gives a orange-red flame?
Calcium Ca2+
Which metal give a lilac flame?
Potassium K+
Which metal gives a yellow flame?
Sodium Na+
Which metal gives a crimson flame?
Lithium Li+
What is hydrochloric acid used for?
Clean the loop/wire (1)
Describe how to carry out a flame test (4)
Dip clean loop into sample
Place in blue flame (bunsen burner)
Write down colour
Clean loop with HCl
Sodium hydroxide and aluminium (1)
Whiteppt
dissolved in excess NaOH
Sodium hydroxide and calcium (1)
White ppt
doesn’t dissolve
Sodium hydroxide and magnesium (1)
White ppt
doesn’t dissolved in excess NaOH
Sodium hydroxide and iron (II) (1)
green ppt
Sodium hydroxide and Iron (III) (1)
red- brown ppt
Sodium hydroxide and copper (1)
Blue ppt formed
What is the test for a sulphate? (1)
white ppt formed
with barium chloride solution
What is the test for a carbonate?
add acid
bubbles of CO2 given off
test gas with limewater
turns clear to cloudy
What is the test for the halides? (2)
Add nitric acid
then silver nitrate
chloride = white ppt Bromide = cream ppt Iodide = yellow ppt
Green flame
Copper Cu2+
orange red flame
Calcium Ca2+
a lilac flame
Potassium K+
yellow flame
Sodium Na+
crimson
Lithium Li+
How do you clean the loop/wire? (flame test)
Clean hot wire
with hydrochloric acid
Sodium hydroxide test produces white ppt
either aluminium, calcium or magnesium
Sodium hydroxide test produces iron (II)
green ion
