More Practice…
You have 3.0 mol of aluminum sulfate. Calculate the following
quantities:
1. The total number of Al atoms.
2. The total number of Al2(SO4)3 formula units.
3. The moles of sulfate ions.
4. The moles of oxygen atoms.
More Practice…
How many mol of ions are present in a 1.0-g sample of zinc
oxide (ZnO)?
Calculate the mass of 4.85 mol of acetic acid, CH3COOH.
2
Balancing Practice
a)
NH3(g) + HCl(g)  NH4Cl(s)
b)
NO(g) +
H2(g) 
c)
Fe2O3(s) +
HNO3(aq) 
N2(g) +
H2O(l)
Fe(NO3)3(aq) +
H2O(l)
d) Dihydrogen sulfide gas reacts with aqueous lead(II) nitrate to form
solid lead (II) sulfide and aqueous nitric acid.
e) Solid ammonium nitrite decomposes to nitrogen gas and gaseous
water.
f) Solid antimony trichloride is formed from its elements at room
temperature.
LRs in Action
CO(g)
+
2H2(g)

CH3OH(l)
Initial
1 mol
2 mol
0 mol
Change
- 1 mol
- 2 mol
+ 1 mol
End
0 mol
0 mol
1 mol
Both reactants are completely used
up…neither CO or H2 limit the
production of CH3OH.
LRs in Action (cont)
CO(g)
+
2H2(g)
CH3OH(l)

Initial
0.5 mol
2 mol
0 mol
Change
- 0.5 mol
- 1 mol
+ 0.5 mol
End
0 mol
1 mol
0.5 mol
CO is used up before H2 …
CO limits the production of
CH3OH.
LRs in Action (cont)
CO(g)
+
2H2(g)
CH3OH(l)

Initial
1 mol
1 mol
0 mol
Change
- 0.5 mol
- 1 mol
+ 0.5 mol
End
0.5 mol
0 mol
0.5 mol
H2 is used up before CO…
H2 limits the production of
CH3OH.