Tests Flashcards
What is the oxygen test?
Take a glowing splint, if it ignites then oxygen is present.
What is the carbon dioxide test?
Take a glowing splint, if it goes out then carbon dioxide is present.
Or limewater turns milky.
What is the test for hydrogen?
Take a lighted splint, if it pops then hydrogen is present.
What is the test for chlorine?
If a damp blue litmus paper bleaches, chlorine gas is present.
What is the general method for the flame tests?
A nichrome wire loop should be dipped in HCl and then heated. It should be dipped in acid again before dipping it into the metal compound being tested.
Hold the loop in the roaring flame of a Bunsen burner.
Use the colour of the Bunsen flame to identify the metal ion in the compound.
What colour do lithium ions turn a flame in the flame test?
crimson
What colour do sodium ions turn a flame during a flame test?
yellow
What colour do potassium ions turn the flame in the flame test?
lilac
What colour do calcium ions turn a flame in a flame test?
orange-red
what colour do copper ions turn a flame in a flame test?
green
What does the flame test identify?
Positive ions
What is the metal cation test?
Reacting unknown compounds with sodium hydroxide solution?
Which ions form white precipitates when reacted with sodium hydroxide?
Aluminium, Calcium and Magnesium.
Which ions form coloured precipitates in the sodium hydroxide test?
Copper (II)
Iron (II)
Iron (III).
What colour precipitate forms when Copper (II) ions are reacted with Sodium Hydroxide?
Blue
