SURVEY OF CHEMISTRY LABORATORY I
CHEM 1151L
REACTIONS OF COPPER
CAUTION!!!
BE SURE TO WEAR SAFETY GLASSES AT
ALL
TIMES IN THE LABORATORY
NO EXCEPTIONS TO THIS RULE!
REACTIONS OF COPPER
- To demonstrate chemical changes
- To investigate the reactions of copper and its compounds
- Students will make a series of compounds with metallic copper
and regenerate the elemental copper at the end
Cu → Cu(NO3)2 → Cu(OH)2 → CuO → CuSO4 → Cu
USES OF COPPER
Copper metal is used for
- Water pipes
- Electrical wiring
- Cookware
- Coins
- Etc
There are extensive uses of the
compounds of copper
- Widely used as pigments
- Copper sulfate (CuSO4) is a fungicide
SAMPLES OF COPPER AND ZINC
PREPARATION OF COPPER(II) NITRATE
- Weigh about 1 gram of copper
metal
- Cut with scissors
- Roll into a ball
- Record your observation of the
copper metal
PREPARATION OF COPPER(II) NITRATE
3Cu + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O
- Work in the hood
- Add 10 mL of 16 M nitric acid
(HNO3) into a clean 250mL
beaker
- Place the metal copper into the
beaker of acid
PREPARATION OF COPPER(II) NITRATE
- Allow the copper to completely
dissolve
PREPARATION OF COPPER(II) NITRATE
- Warm the solution gently to
remove excess nitric acid
(brownish-red gas)
- Stop warming after all traces of
brownish-red gas are gone
- Avoid excessive boiling
PREPARATION OF COPPER(II) NITRATE
- Observe and record the
properties of copper(II)
nitrate
- Use litmus paper to test
acidity of solution
- Blue litmus paper will turn red
if solution is acidic
PREPARATION OF COPPER(II) HYDROXIDE
Cu(NO3)2 + 2NaOH → Cu(OH)2 + 2NaNO3
- Allow the beaker to cool
- Place the beaker in an ice bath
- Add 15 mL of 6 M sodium
hydroxide (NaOH) dropwise
with stirring
PREPARATION OF COPPER(II) HYDROXIDE
- Use litmus paper to test if solution is
basic
- Add a drop of the mixture to a strip of
red litmus paper
- Blue color indicates the solution is
basic
- The solution itself is blue so watch the
“bleeding” portion
PREPARATION OF COPPER(II) HYDROXIDE
- Add more NaOH as necessary (drop by drop) until the
solution is basic
- Rinse stirring rod into the solution when being removed from
the solution
- Rinse the sides of the beaker into the solution
- Record all observations
PREPARATION OF COPPER(II) OXIDE
Cu(OH)2 + heat → CuO + H2O
- Add 50 mL of distilled water to
the beaker containing Cu(OH)2
PREPARATION OF COPPER(II) OXIDE
- Gently boil the solution
while stirring continuously
- Boil for an additional minute
after a distinct color change
is observed
- Record all observations
PREPARATION OF COPPER(II) SULFATE
CuO + H2SO4 → CuSO4 + H2O
- Allow CuO to settle
- Pour off the clear liquid into another
beaker
- Be careful not to lose any of the solid
material (CuO)
- Add 50mL of distilled water and stir
- Pour off the water once settled
- Repeat the process twice
PREPARATION OF COPPER(II) SULFATE
- Stir the mixture
- Add concentrated sulfuric acid
(H2SO4) dropwise until all of
the CuO dissolves
- A distinct color change will be
observed
- Record all observations
PREPARATION OF COPPER(II) SULFATE
- Add about 3 grams of zinc
to the CuSO4 solution
- Cover the solution with
Parafilm
- Store it in a cabinet
END OF FIRST LAB PERIOD
PREPARATION OF COPPER
CuSO4 + Zn → Cu + ZnSO4
- Solution should turn from blue
to colorless after all copper has
reacted
PREPARATION OF COPPER
CuSO4 + Zn → Cu + ZnSO4
- Stir for solution to become
colorless if the solution is still
blue
- Consult instructor before
advancing to the next step
PREPARATION OF COPPER
Zn + 2HCl → H2 + ZnCl2
- Work in the hood
- Slowly add 5-10 mL of 12 M
hydrochloric acid (HCl) to the
solution
PREPARATION OF COPPER
- Remove excess pieces of zinc with forceps
- Use a wash bottle of distilled water to rinse the copper off
the pieces of zinc as they are removed
- Mass and record a piece of filter paper and Petri dish
together
PREPARATION OF COPPER
- Allow the copper to settle
- Place the filter paper in a
Buchner funnel
PREPARATION OF COPPER
- Filter the solution through the
Buchner funnel
PREPARATION OF COPPER
- Allow the funnel to drain
completely
- Wash the copper with distilled
water followed by acetone
- Use small amounts
PREPARATION OF COPPER
- Place the filter paper and copper
on the massed Petri dish
- Dry it in the oven for a few
minutes
- Make sure the filter paper does
not burn
- Remove immediately when filter
paper starts to turn brown
PREPARATION OF COPPER
- Remove sample from oven and
allow to cool
- Mass copper together with filter
paper and Petri dish
- Determine the mass of the copper
recovered in your experiment
- Calculate percent recovery
CLEAN UP
- Dispose of copper into the appropriate waste container
- Clean all glassware
- Return all equipment to their proper places