# Identify the bottles

## Homework Statement

Identify the bottles

2. Homework Equations

## The Attempt at a Solution

Bottle 1 is lead nitrate as lead is the only metal that will form a precipitate with the other anions.

Bottle 3+4 = copper sulfate + sodium carbonate -- because it produces blue precipitate

Bottle 2+3 = hydrochloric acid + sodium carbonate -- as acid + metal = salt + hydrogen gas.

This means sodium carbonate is bottle 3, hydrochloric acid is bottle 2, and copper sulfate is bottle 4. Can someone check this?

If this is correct, out of interest, why doesn't hydrogen gas evolve when HCl is added to lead nitrate and copper(II) sulfate?

Cheers!

Merlin3189
Homework Helper
Gold Member
2+3 : Sodium carbonate is not a metal and the gas is not hydrogen.
That should also explain why HCl does not produce a gas with PbNO3 or CuSO4

TT0
I see, I forgot. CO2 and water are evolved, not H2! Other than that, is the rest of the answers correct?

Cheers!

Merlin3189
Homework Helper
Gold Member
If I have deduced correctly from your statements, you are saying;
1 - PbNO3
2 -HCl
3- Na2CO3
4 - CuSO4

So that means;
1 & 2 is lead nitrate + HCl -> white precipitate of
1 & 3 is lead nitrate + sodium carbonate -> white precipitate of
1 & 4 is lead nitrate + copper sulphate -> white precipitate of
2 & 3 is HCl + sodium carbonate -> gas produced = CO2
2 & 4 is HCl + copper sulphate -> no visible reaction
3 & 4 is sodium carbonate + copper sulphate -> blue precipitate of
all plausible, so you are correct.
You could write out the equations for each, apart from the no reaction, if you wanted to make clear what was happening.

TT0
I see, cheers!