DETECTING CATIONS

What ion and flame test colour would you get for lithium?

Ion = Li(+)

Flame test colour = red

What ion and flame test colour would you get for sodium?

Ion = Na(+)

Flame test colour = yellow

What ion and flame test colour would you get for potassium?

Ion = K(+)

Flame test colour = lilac

What ion and flame test colour would you get for calcium?

Ion = Ca (2+)

Flame test colour = orange-red

What ion and flame test colour would you get for copper?

Ion = Cu(2+)

Flame test colour = green-blue

What is the method for doing a flame test? (3 steps)

1. Dip the clean nichrome loop into the test powder or solution

2. Use the handle to hold the loop in the edge of a roaring blue flame

3. Record the flame colour

What is the formula of the ion and colour of hydroxide precipitate of iron (II)

formula of ion = Fe(2+)

colour of hydroxide precipitate = green

What is the formula of the ion and colour of hydroxide precipitate of iron (III)

formula of ion = Fe(3+)

colour of hydroxide precipitate = orange-brown

What is the formula of the ion and colour of hydroxide precipitate of copper (II)

formula of ion = Cu(2+)

colour of hydroxide precipitate = blue

What is the formula of the ion and colour of hydroxide precipitate of calcium

formula of ion = Ca(2+)

colour of hydroxide precipitate = white

What is the formula of the ion and colour of hydroxide precipitate of zinc

formula of ion = Zn(2+)

colour of hydroxide precipitate = white

Since calcium hydroxide and zinc hydroxide are both white, how can u distinguish them?

If you add an excess of sodium hydroxide solution, zinc hydroxide dissolves to form a colourless solution but calcium hydroxide does not dissolve