Name ___________________________________________________
Ionic Formulas Lab II
1. Write a complete, balanced equation for the reaction between aqueous solutions of copper (II) chloride and sodium phosphate.
3 CuCl2 (aq) + 2 Na3PO4 (aq)
 6 NaCl (aq)
+
Cu3(PO4)2 (s)
2. Write an overall ionic equation for the reaction.
3 Cu2+ (aq)
6 Cl- (aq) + 6 Na+ (aq) + 2 PO43- (aq)
 6 Na+ (aq)
+ 6 Cl- (aq) + Cu3(PO4)2 (s)
3. Write a net ionic equation for the reaction.
3 Cu2+ (aq)
Test Tube
# of drops of
0.1 M CuCl2
# of drops of
0.1 M
Na3PO4
Ratio of Cu2+
to PO43Draw each
tube and
label the
color of the
solution
above the
precipitate.
Limiting
reagent
excess
reagent
+
+ 2 PO43- (aq)  Cu3(PO4)2 (s)
#1
3
#2
6
#3
12
#4
15
#5
18
#6
24
#7
27
27
24
18
15
12
6
3
1:9
1:4
2:3
1:1
3:2
4:1
9:1
CuCl2
CuCl2
CuCl2
CuCl2
Na3PO4
Na3PO4
Na3PO4
Na3PO4
Na3PO4
Na3PO4
CuCl2
CuCl2
4. Which test tube had the most precipitate?
5. According to the formula for the precipitate, which tube should theoretically have the most precipitate? #5
6. If there is a difference between the actual and the theoretical, give a logical explanation for the difference.
7. After compete mixing, which tubes should have Cu2+ ions in solution above the precipitate? #6 and #7
8. How could you provide evidence that there are Cu2+ ions still in solution in test tube #7, but not in test tube #1?
9. How many total drops of CuCl2 would be needed to precipitate out all the PO43- ions in test tube # 2? 36 drops
10. How many total drops of Na3PO4 would be needed to precipitate out all the Cu2+ ions in test tube #6? 18 drops
11. After complete mixing, which ions are still in solution above the precipitate in test tube #4? Na+ Cl- PO43-