Chemical change or physical change?

Are you changing the substance when you cool copper sulphate solution?? No.. As a solution, copper and sulphate ions floating around in water...

When you cool it, they get together, and form a crystal with copper ions and sulphate ions in specific lattice formations.. they are still copper ions and sulphate ions.. so no chemical change here... only physical change..

When you are heating the lead oxide with carbon and extracting lead, what are you doing?? lead oxide is a different chemical substance from lead.. what is happening to the carbon?? it reacts with the oxygen removed from lead oxide, and forms carbon dioxide.. so.. there is a chemical reaction here...

the first one cooling a saturated copper sulphate solution to form crystals is a physical change since there is no change of chemical prooperties of the substance. Onlt the physical properties change. Example change of any state solid-liquid-gaseous.

On the other hand the second one heating lead oxide with carbon to extract lead is a chemical change as it changes the chemical properties of the substance(s). For Example when Hydrogen ie is a gas react with Oxygen (also a gas) they form a liquid(Water).

The first is physical because the chemical nature of the copper sulphate is what allows it to form the crystals.

For the second, I think it would be chemcial because the lead looses the oxide. I'm not sure if this is because of the carbon and the heat or because of just the heat.

cooling a saturated copper sulphate solution is a physical change

heating a lead oxide with carbon to extract a lead is a chemical change

The first one is chemical. You are only cooling.

The second one is chemical. You have lead oxide and are changing the chemical structure of this molecule with a reaction to get elemental lead.

I would say it's too little information to tell. If you mix red paint and yellow paint...you get orange paint. But this isnt a chemical change, it's physical. However that doesn't mean that a red compound won't react with a yellow compound to produce an orange one.

the first one is physical but not sure about the second I think it's chemical

1.Physical

2.chemical