Lab 3 - Copper Compounds

Cu(OH)₂ (solubility or state of matter)

Copper(II)hydroxide (S)

Copper(II)oxide (color) (solubility or state of matter)

CuO (black) (solid)

Nitric acid (solubility or state of matter)

HNO₃ Aqueous

copper(II)nitrate (solubility or state of matter)

Cu(NO₃)₂ Aqueous

Reaction 1

Oxidation reduction reaction: Oxidation of copper by nitric acid

Cu + 4NHO₃—>Cu(NO₃)₂+2(NO₂)+2(H₂O)

Copper + Nitric Acid = copper(II) nitrate

• Nitric acid added to copper

• blue solution of copper(II) nitrate formed

• nitrogen dioxide gas is released (brown)

• water added to solution

Reaction 2

Double displacement of copper(II)nitrate with NaOH:

Cu(NO₃)₂+2NaOH—-→Cu(OH)₂+2NaNO₃

• Sodium Hydroxide added to copper(II)nitrate

• Blue Copper(II)hydroxide is formed

Reaction 3

The decomposition of copper(II)hydroxide:

Cu(OH)₂—→CuO + H₂O

• Copper(II) hydroxide is heated

• Copper(II) oxide formed

• Water added

Reaction 4

Double displacement of copper(II)oxide with H₂SO₄

CuO + H₂SO₄ ——→ CuSO₄ + H₂O

• sulfuring acid added to copper(II) oxide

• copper(II) sulfate formed

• water added

Reaction 5

Single displacement of copper(II) sulfate with zinc

CuSO4 + Zn ——> Cu + ZnSO4

• Zinc is added to copper(II) sulfate 

  • from blue to black

• hydrogen gas is produced

• copper is separated from zinc and sulfate via Buchner funnel

Percent recovery

g of element recovered / initial g of element recovered x 100%

When you have finished adding the necessary amount of NaOH to your beaker, what color will the litmus paper turn?

blue

Reaction #5 must be carried out under the hood due to the production of the flammable _______ gas. 

hydrogen

What substance is used to help dry your sample rapidly?

Acetone

What substance will you use to dissolve the copper(II) oxide?  Give the name, not the formula (two words).

Sulfuric acid (H₂SO₄)

What is decanting and how do you do it properly?

moving solution from one container to another. should be done under fume hood depending on reagents, you should never pour while at eye level, pour and then check. Place excess into labeled excess container.

How is filtering done properly

Buchner funnel