Balancing Equations
The Mole Concept
Molar Conversions
Stoichiometry
100
Balance the equation:
___H2 + ___O2 --> ___H2O
2H2 + O2 --> 2H2O
100
Magnesium bromide is a ___________ (ionic or covalent) compound and has ____________ (atoms, formula units, or molecules) as its representative particles.
Ionic, formula units
100
What is the volume of 2 moles of hydrogen gas at STP?
2 moles H2 x 22.4L/1mole = 44.8 L
100
For the following reaction:

2H2 + O2 --> 2H2O

If you start with 64 grams oxygen gas, how many moles of water will be produced?
64g O2 x 1mole/32g x 2mol H2O/1mol O2 = 4 mol H2O
200
Predict the products and balance:

Synthesis

___Mg + ___O2 --> ________________
2Mg + O2 --> 2MgO
200
One mole of oxygen gas at STP has a volume of _____________ L
22.4 L
200
How many moles of sodium chloride are there in 1.204x1024 formula units?
1.204x1024 r.p. NaCl x 1mole/6.02x1023r.p. = 2 moles
200
For the following reaction:

2NaCl + F2 --> 2NaF + Cl2

If you start with 4 moles of sodium chloride, what volume of chlorine gas will be produced at STP?
4mol NaCl x 1mol Cl2/2mol NaCl x 22.4L/1mol = 44.8 L Cl2
300
Predict the products and balance:

Double replacement

___NaCl + ___CaF2 --> ______________________
2NaCl + CaF2 --> CaCl2 + 2NaF
300
One mole of Calcium fluoride has a mass of ___________ grams.
CaF2

Ca: 40g x 1 = 40g
F: 19g x 2 = 38g

78 grams
300
What is the mass of 3 moles of carbon dioxide?
3 mol CO2 x 44g/1mol = 132g

C: 12g x 1 = 12g
O: 16g x 2 = 32g
300
2H2O --> 2H2 + O2

If you start with 18g of water, how many r.p.s of hydrogen gas will be produced?
2H2O --> 2H2 + O2

18g H2O x 1mol/18g x 2mol H2/2mol H2O x 6.02x1023r.p./1mol = 6.02x1023r.p. H2
400
Write and balance an equation:

Combustion of dicarbon tetrahydride.
C2H4 + 3O2 --> 2CO2 + 2H2O
400
One mole of Magnesium bromide contains ______________ representative particles and ___________atoms
MgBr2

6.02x1023 r.p.
1.806x1024 atoms
400
What is the volume of 40 grams of water vapor (gas form of water) at STP?
40 g H2O x 1mole/18g x 22.4L/1mole = 49.8 L

H: 1g x 2 = 2g
O: 16g x 1 = 16g
400
Balance the following combustion equation and then solve the stoichiometry problem:

___C3H4 + ___O2 --> ___CO2 + ___H2O

Given: 3 moles CO2
Unknown: ? g H2O
C3H4 + 3O2 --> 3CO2 + 2H2O

3mol CO2 x 2mol H2O/ 3mol CO2 x 18g/1mol = 36g H2O
500
Write and balance an equation:

Single replacement reaction between zinc (II) oxide and sodium.
ZnO + 2Na --> Na2O + Zn
500
The percent composition by mass of each element in C2H3O2 is:

_____ % C
_____ % H
_____ % O
C: 12g x 2 = 24g
H: 1g x 3 = 3g
O: 16g x 2 = 32g


total mass= 59 g

%C = 24g/59g = 41% C
%H = 3g/59g = 5% H
%O = 32g/59g = 54% O
500
How many atoms are there in 56g of carbon monoxide?
56g CO x 1mol/28g x 6.02x1023r.p/1mole x 2atoms/1r.p. = 2.408x1024
500
___MgO + ___S --> ___MgS + ___O2
Balance the equation and do the stoichiometry problem below:
If the reaction starts with 16g sulfur, how many grams of the compound product will be produced?
2MgO + 2S --> 2MgS + O2

16g S x 1mol/32g x 2mol MgS/ 2mol S x 56g/1mol = 28g MgS

mass MgS Mg: 24g x 1 = 24g S: 32g x 1 = 32g total= 56 g
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