Sodium Hydroxide + Copper Sulfate
How was mass conserved?

Yes, mass is conserved. In any chemical reaction mass is neither created, nor destroyed.  If you with to demonstrate this conservation by the reaction of sodium hydroxide with copper sulfate, you can do so by measuring the mass of all reactants and reaction vessels both before and after the reaction.

Explanation:

Yes, mass is conserved. In any chemical reaction mass is neither created, nor destroyed. ... If you with to demonstrate this conservation by the reaction of sodium hydroxide with copper sulfate, you can do so by measuring the mass of all reactants and reaction vessels both before and after the reaction.

Explanation:

they it depends on if one believes about radioactivity, they make a geiger counter beep but maybe it was going to beep anyway electronics do wierd things all the time or it was programmed to beep near certain metals.

what is the question here. i think you messed up.