The Empir(ical) Strikes Back
ID EQ
Seeking Balance
Mole to Mole
Grab Bag
100
What is the empirical formula for C5H12O6?
C5H12O6 is the empirical formula
100
What type reaction is: 2KClO₃ → 2KCl + 3O₂
decomposition reaction
100
Zn + HCl --> ZnCl2 + H2
When you balance this equation,what is the sum of the coefficients?
Zn + 2HCl ---> ZnCl2 + H2
1+2+1+1 =5
100
How many moles of O2 are required to completely react with 2.0 moles of Al?
2 mol Al x (3 mol O2/4 mol Al)
X =1.5 mol O2
100
Formula 1: CH2
Formula 2: C4H8
What kind of formulas are these?
Formula 1: empirical
Formula 2: molecular
200
Could these two formulas represent the same compound? Explain.
CH3 and C3H9
Yes, they can represent the same compound CH3 is the empirical formula, C3H9 is the molecular formula.
200
Identify this reaction:
CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g)
combustion
200
Ca(OH)2 + H3PO4 ---> Ca3(PO4)2 + H2O
When this is balanced, what is the coefficient in front of Ca3(PO4)2
3Ca(OH)2 + 2H3PO4 ---> Ca3(PO4)2 + 6H2O
1
200
How many moles of Al are necessary to product 0.60 moles of Al2O3?
0.60 mol Al2O3 X (4 mol Al/2 mol Al2O3) = 1.2 mol Al
200
Balance the following equation. What is the sum of the coefficients?
P4 + Cl2 --> PCl3
P4 + 6Cl2 --> 4PCl3
1+6+4 = 11
300
A compound is 75.69% C, 8.80% H, and 15.51% O. What is the empirical formula?
75.69g C/12.01g= 6.302 mol/0.969 mol= 6.5x2=13
8.80gH/10.1g=8.713mol/0.969=9 x 2 =18
15.51gO/16.00g=0.969mol/0.979= 1 x 2 = 2
C13H18O2
300
KOH + H2SO4 ---> K2SO4 + H2O
What is the name of this reaction?
double replacement
300
FeCl3 + NH4OH ---> Fe(OH)3 + NH4Cl
FeCl3 + 3NH4OH ---> Fe(OH)3 + 3NH4Cl
300
How many moles of O2 are necessary to produce 3.2 moles of SO3?
3.2 mol SO3 x (12 mol O2/8 mole SO3)=
4.8 mol O2
300
P4 + 6Cl2 --> 4PCl3
If 1.5 moles of PCl3 are produced, how many moles of Cl2 were originally present?
1.5mol PCl3 x (6 mol Cl2/4 mol PCl3) =
2.3 mol Cl2
400
A compound is made of 54.%C, 9.1%H, and 36.4% O. What is its empirical formula?
54.5g C/12.01g= 4.538mol/2.275mol = 2
9.1g H/1.01g=9.010mol/2.275 mol = 4
36.4g O/16.00g= 2.275mol/2.275mol =1
C2H4O
400
ID this reaction: CaCO3 + HCl ---> CaCl2 + H2CO3
double replacement
400
S8 + F2 ---> SF6
S8 + 24F2 ---> 8SF6
400
How many moles of S8 are required to completely react 2.7 mol of O2?
2.7 mol O2 x ( 1 mol S8 / 12 mol O2) =
0.23 mol S8
400
Analysis of a sample of a covalent compound showed that it contained 14.4% hydrogen and 85.6% carbon by mass. What is the empirical formula for the compound?
H: 14.4 g/1.01 g/mol = 14.2 mol/7.12 =2
C: 85.6 g/12.01 g/mol= 7.12 mol/7.12= 1
CH2
500
A compound with empirical formula C2H4O has a molecular mass of 88 g. What is the molecular formula?
C2H4O has mass 2(12.01) + 4(1.01) + 16.00= 44.06g.
The #units = 88g/44.06g= 2 units => C4H8O2
500
2CO + O2 ---> 2CO2
What is this reaction?
synthesis
500
Al + 2HCl → AlCl3 + H2
2Al + 6HCl → 2AlCl3 + 3H2
500
Fe + 6O2 ---> 3Fe3O4
How many moles of Fe3O4 are produced if 4.2 moles of O2 are consumed?
4.2 mol O2 x (3 mol Fe3O4/6 mol O2) =
2.1 mol Fe3O4
500
FeCl3 + 3NH4OH ---> Fe(OH)3 + 3NH4Cl
What is the mole ratio of FeCl3 to NH4OH?
1 : 3