Reaction #1: Reactions of Copper

Question 1

Reaction #1 of Copper

Answer 1

Solid Cu wire + HNO3 -> Cu(NO3)2 + NO2 + H2O
Deep blue solution

Question 2

Reaction #2 of Copper

Answer 2

Dilute Cu(NO3)2
Add NaOH, makes Cu(OH)2 + NaNO3
Dark blue solid

Question 3

Reaction #3 of Copper

Answer 3

Heat solution about 1min
Vacuum filter sol’n with buchner funnel, using DI to rinse
Cu(OH)2 -> CuO + H2O
Powdery black solid

Question 4

Reaction #4 of Copper

Answer 4

Add H2SO4 to rinse, swirl
CuO + H2SO4 -> CuSO4 + H2O
Solution turns bright blue

Question 5

Reaction #5 of Copper

Answer 5

Add Zinc to solution (in little bits)
Redox reaction
CuSO4 + Zn -> ZnSO4 + Cu
Brown powdery solid

Question 6

Reaction #6 of Copper

Answer 6

Add HCl and swirl
Zn disappears
Decant solution, transfer to evaporating dish and heat
Zn + HCl -> ZnCl2 + H2

Question 7

Calculating % Yield

Answer 7

(final)/(initial) x 100%

Question 8

Calculating % atom economy

Answer 8

(molar mass of desired product)/(Molar mass of all reactants) x 100%

Question 9

What would have happened if HCl was used instead of H2SO4

Answer 9

Solution would turn green (CuCl2 would form)

Question 10

Why was excess NaOH used?

Answer 10

Because there was excess HNO3 present

Question 11

Filtrate

Answer 11

Solution which the precipitate is filtered from

Question 12

Decant

Answer 12

Carefully pouring out solution leaving precipitate behind

Question 13

Supernatant

Answer 13

Liquid over a precipitated solid

Question 14

Bumping

Answer 14

When precipitate forms as a layer on the surface of the solution, hot air gets trapped and forms a bubble until it bursts (splatters)