Copper Reaction (Discussion)

The initial mass of copper wire was 1.250g but the recovered copper was only 0.120 subtracting the mass of the recovered copper with beaker from the tare beaker mass. So the percentage yield resulted only to 9.6% it is very little, and it may be due to many possible sources from doing the steps. Adding too much or too little of a compound to the copper solution,or the loss of copper during transport or by being left on the stirring rod. Another situation which was a source of error is when the copper solution and water was heated so that the contents of the beaker would boil. The error in this step was caused by the variable heating of the solution to prevent bubbling of the solution.
The reaction of copper with nitric acid resulted in a brown toxic gas, As the copper dissolved, the solution slowly turned blue because of the copper ions. this is the balanced equation for the reaction Cu(s) + 4H+(aq) + 2NO3-(aq)---> Cu2+(aq) +2NO2(g) + 2H2O(l) The reaction of aq copper nitrate with sodium hydroxide was the turning of the solution to a blue color, when water was added a cloudy mass of blue was formed below. This precipitate was copper (II) hydroxide. The precipitate was blue because of the copper ions. the balanced equation for this is Cu2+(s) + 2OH-(s) ---> Cu(OH)2O(s) The third reaction copper (II) hydroxide solution was heated, the solution turned from a bright blur precipitate turned into a black color and black precipitates were formed this is the reaction Cu(OH)2(s)---> CuO(s) + H2O(l) The fourth reaction, when copper (II) oxide was dissolved into 6M sulfuric acid the solution turnes into a blue-green color, in the end it turned into blue. The reaction is CuO(s) + 2H+(aq)---> Cu2+(aq) + H2O(l) When Zn metal is added to copper (II) sulfate it released a foul smelling gas which was hydrogen, , the Zn corroded into red precipitates but the solution retained its blue color. the reaction is Cu2+(aq) + Zn(s)---> Cu(s) +