reactions/tests Flashcards
How do you carry out a flame test?
- Dip a clean wire loop into the solid compound being tested
- Put the loop into the blue flame
- Observe and record colour produced
What colour does Lithium give out?
Crimson
What colour does Sodium give out?
yellow
What colour does Potassium give out?
lilac
What colour does Calcium give out?
orange-red
What colour does Copper give out?
green
What dilute solution is used in metal ion tests?
sodium hydroxide
Are metal hydroxides soluble?
No
What is the precipitate colour given from Aluminium (Al3) + Sodium hydroxide? And how else do we identify it if excess sodium hydroxide is added?
White
Dissolves to form a colourless solution
What is the precipitate colour given from Calcium (Ca2) + Sodium hydroxide?
White
The precipitate is unchanged
What is the precipitate colour given from Magnesium (Mg2) + Sodium hydroxide?
White
The solution is unchanged
What is the precipitate colour given from Copper (Cu2) + Sodium hydroxide? (this is a transition metal)
Blue
What is the precipitate colour given from Iron II (Fe2) + Sodium hydroxide? (this is a transition metal)
Green
What is the precipitate colour given from Iron III (Fe3) + Sodium hydroxide? (this is a transition metal)
Brown
What is the test for Ammonia, 2NH3?
add sodium hydroxide and warm, a pungent smelling gas (white gas) is formed which turn red litnus paper blue