Test for cations (using aqeuous sodium hydroxide)

Question 1

What will happen when aqeuous sodium hydroxide is added to Ca2+ ion?

Answer 1

A white ppt is formed, insoluble in excess of aqeous sodium hydroxide.

Question 2

What will happen when aqeuous sodium hydroxide is added to Zn2+ ion?

Answer 2

A white ppt is formed, soluble in excess aqeuous sodium hydroxide to give a colourless solution.

Question 3

What will happen when aqeuous sodium hydroxide is added to Al3+ ion?

Answer 3

A white ppt formed, soluble in excess of aqeuous sodium hydroxide to give a colourless solution.

Question 4

What will happen when aqeuous sodium hydroxide is added to Pb2+ ions?

Answer 4

A white ppt is formed, soluble in excess of aqeous sodium hydroxide to give a colourless solution.

Question 5

What will happen when sodium hydroxide is added to Fe2+ ion?

Answer 5

A green ppt is formed, insoluble in excess of sodium hydroxide solution.

Question 6

What will happen when sodium hydroxide is added to Fe3+ ion?

Answer 6

A reddish-brown ppt is formed, insoluble in excess of sodium hydroxide solution.

Question 7

What will happen when sodium hydroxide is added to Cu2+ ion?

Answer 7

A blue precipitate is formed, insoluble in excess of aqeous sodium hydroxide solution.