CHEMISTRY REVIEW
STOICHIOMETRY
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Name and write the chemical formulas for the diatomic elements (hint: they are all gases) that exist as
molecules on the surface of the earth. (look them up in the book!) … and write them down.
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Convert chemical names into chemical formulas for ionic compounds, balancing the charges correctly.
Look up charges on anion/cation handout. Adjust number of atoms or groups of atoms until charges
balance.
For example: Sodium Phosphate. Sodium is Na+, Phosphate is PO43—, in order to balance the charge,
you need 3 of the Na+ ions to get a total charge of +3 which balances the —3 charge of the phosphate,
so the formula is Na3PO4
Problems: write the chemical formulas for:
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1. Calcium Chloride
2. Sodium Nitrate
3. Rubidium Phosphate
4. Ammonium Nitrate
5. Barium Phosphate
6. Aluminum Acetate
Convert chemical names into chemical formulas for non-ionic compounds
Write the formula literally from the name.
For example: Carbon Tetrachloride. ‘tetra’ means 4 so the formula literally means carbon with four
chlorines. So the formula is CCl4 … or for molybdenum trioxide the formula is MoO 3
Problems: write the chemical formulas for:
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7. Carbon Monoxide
8. Carbon Dioxide
9. Titanium Tetraflouride
10. Uranium Hexachloride
11. Molybdenum Trioxide
12. Dialuminum Trioxide
Calculate molar mass
Add the atomic mass of each atom in the formula.
For example: Sodium Chloride – NaCl … 23 g/mol + 34.5 g/mol = 57.5 g/mol .
Or for sodium phosphate – Na3PO4 … 3 × 23 g/mol + 31 g/mol + 4 × 16 g/mol = 164 g/mol
Problems: calculate the molar mass for:
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13. Hydrogen
14. Bromine
15. Carbon Monoxide
16. Calcium Chloride
17. Sodium Nitrate
18. Rubidium Phosphate
19. Ammonium Nitrate
20. Barium Phosphate
21. Aluminum Acetate
Convert the number of moles of a gas to a volume and vice versus …
By multiplying or dividing by 22.4 liters/mol , knowing that there are 22.4 liters per mole of a gas or 1
mole of gas occupies a volume of 22.4 liters.
For example: 10 moles of helium is
…
10 moles × 22.4 liters/mol = 224 liters of helium
Or for 44.8 liters of radon … 44.8 liters ÷ 22.4 liters/mol = 2 moles of radon
Problems: answer the following:
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22. 15 moles H2 to liters
23. 5.5 moles CO2 to liters
24. 2500 moles SF6 to liters
25. 20 liters H2 to moles
26. 35 liters CO2 to moles
27. 1500 liters SF6 to moles
Convert the number of moles of a compound into a mass and vice versus …
By multiplying or dividing by the molar mass of the compound
For example: 10 moles of helium × 4 g/mol = 40 grams of helium
Or for 100 grams of gold (Au) … 100 g ÷ 197 g/mol = 0.51 moles of gold
Problems: answer the following:
28. 10 grams Calcium Chloride
To moles
29. 250 grams Sodium Nitrate
To moles
30. 5 grams Rubidium Phosphate
To moles
31. 5 moles Ammonium Nitrate
To grams
32. 1.5 moles Barium Phosphate
To grams
33. 250 moles Aluminum Acetate
To grams
Write a skeleton equation
Translate chemical names into chemicals formulas first, then write the equation.
For example: hydrogen plus oxygen yields water
Problems: answer the following:
…
H2 + O2  H2O
34. Reactants: Calcium Chloride and Sodium Sulfate
35. Reactants: Ammonium Nitrate and Barium Phosphate
36. Reactants: Rubidium Phosphate and Aluminum Acetate
37. Reactants: Rubidium Phosphate and Sodium Nitrate
38. Reactants: Propane (C3H8) and oxygen
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Balance a skeleton equation
Count all the atoms on each side of the equation (reactants and products), adjusts the quantity of of
each molecule under all the numbers of atoms on each side balance.
For example: In H2 + O2  H2O there are 2 hydrogen atoms and 2 oxygen atoms on the reactant side
(the left) and 2 hydrogen atoms and 1 oxygen on the product side (the right). To balance, doubling the
water molecules gives 4 hydrogen atoms and 2 oxygen atoms on the right, then doubling the hydrogen
on the left balances, yielding a balanced reaction of 2H2 + O2  2H2O, which has 4 hydrogen atoms and
2 oxygen atoms on each side of the reaction.
Problems: Balance the skeleton equations in (a) to (e) above.
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Do Stoichiometry
Using the balanced the reaction, determine quantities. The general process is:



 convert given  
wanted   conversion 

   mole ratio of


given   from moles 
 amount to moles  
To convert TO moles … divide by molar mass of given if in grams or divide by 22.4 liters/mol if
given liters of a gas.
The mole ratio comes from the balanced reaction
To convert FROM moles … multiply by molar mass of want answer in grams or multiply by
22.4 liters/mol if want answer in liters (gases only!)
For example: the reaction of zinc and hydrochloric acid yields zinc chloride and hydrogen gas. If 100
grams of zinc is given, how much hydrogen is produced?
 convert given  
wanted   conversion 

   mole ratio of


given   back to moles 
 amount to moles  
balanced reaction
Zn + 2HCl  ZnCl 2 + H 2 (gas)
100 g Zn
 65.4
   1 mol Zn2    2
1 mol H
g
mol
g
mol


1 mol H
100 g Zn  65.4 g mol    1 mol Zn2    22.4


H 2   3.06 grams H 2
liters
mol
  34.25 liters H 2
Problems:
39. Reactants: Cesium Chloride and Sodium Sulfate.
How much Sodium Sulfate is needed to react with 100 grams of Cesium Chloride?
40. Reactants: Ammonium Chloride and Barium Phosphate
Given 10 grams of Barium Phosphate, how much Ammonium Phosphate is produced?
41. Reactants: Rubidium Phosphate and Aluminum Acetate
Given 200 grams of Rubidium Phosphate, how much Rubidium Acetate is produced?
42. Reactants: Rubidium Phosphate and Sodium Nitrate
How much Sodium Nitrate is needed to produce with 10 grams of Rubidium Nitrate?
43. Reactants: Propane (C3H8) and oxygen
What is the mass (and volume) of Carbon Dioxide and water that is produced when 100 liters of
propane is burned? How much oxygen was required to completely burn the 100 liters of propane?
GAS LAWS
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Explain the ‘Kinetic Theory of Gases”
Explain what an Ideal Gas is.
Explain how temperature affects a gas.
Explain what gas pressure is.
Explain why temperature changes gas pressure.
Write the Ideal Gas Law and Combined Gas Law and use them.
Ideal Gas Law: PV  nRT
Combined Gas Law:
PV
PV
1 1
 2 2
n1T1 n2T2
liters × kPa
mole × K
For example, if the temperature is 10 C and there are 5 moles of radon in a 5 liter container, what is the
pressure and what is the mass of radon present?
R  8.31
Ideal Gas Law: PV = nRT P × 5 liter = 5 moles × 8.31 × (273 + 10) P = 2352 kPa
Mass of Radon = 5 moles × molar mass of radon = 5 moles × 222 grams/mole = 1110 grams = 1.11 kg
For example: if the volume of the container of radon is now tripled, what is the new pressure in the
container?
Combined gas law with n and T constant:
P1 × V1 = P2 × V2 2352 kPa × 5 liter = P × 15 liter P = 784 kPa
Problems:
44. A balloon has a volume of 100 liters at 0.5 atom pressure and a temperature of -10 C. How much
gas in the balloon. (ideal gas law)
45. A rocket tank has a volume of 25,000 liters. How much oxygen gas (in kilograms) does the tank
contain if the temperature of the oxygen gas is –75 C and the tank pressure is 200 atm? (ideal gas
law)
46. A helium tank container 25 liters of helium gas at a pressure of 200 atm. If the helium is used to fill
2 liter balloons, how many balloons can be filled? (combined gas law)
47. An underground salt down can hold 25 million liters of gas. If carbon dioxide gas is pumped down
into the salt down where the temperature is 35 C and the pressure is 250 atm, what mass of
carbon dioxide can be stored there? (combined gas law)
48. A monopropellant rocket engine takes sulfur hexafluoride gas at a pressure of 500 atm and a
temperature of -75 C and heats the gas to a temperature of 10,000 C in order to expand the gas to
a pressure of 0.0001 atm. If 1 liter of gas is heated, what is it’s new volume? (combined gas law)
Given three examples of units of measurement which can be converted in grams.
What is the relationship between milliliters and grams?
What is the result of converting 1.65 liters to milliliters?
What are the differences, similarities between protons, electrons, and neutrons?
For the first four elements in the halogen group and in the alkali metals group, what are the number of
protons (p), number of neutrons (n), and number of electrons (e−).
The atomic number of an element is total number of which particles in the nucleus?
The mass number of an element is equal to __________________________.
What is an isotope?
What is difference between an isotope of an element and atoms of the elements which are not isotopes?
All atoms of the same element have the same _________________________.
Ions form when atoms gain or lose _____________________________.
What type of ions have names that end in –ide?
For the first four elements in the alkaline earth group and elements in group 5A, write the symbol and
name of the ions.
Write the correct name for the following ionic compounds: MgF2, NaNO3, AL(CN)3, PbO, MgO, Be2SO4,
KCl, Na2CO3, NaOH, CaO, FeCl3
Write the correct chemical formula for the following ionic compounds: sodium chloride, titanium (IV)
iodide, aluminum nitrate, iron (II) chloride, iron (III) chloride, magnesium chloride, magnesium chlorate,
silver sulfide, ammonium hydroxide, sodium arsenate.
When the equation showing the ionic reaction between iron (II) ions and chloride ions is written, what is
the coefficient for the chloride (i.e. how many chlorides are needed for every iron (II) ion?
Chemical equations show ______________________.
What is a ‘molecule’? a ‘molecular compound’? Give at least two examples of each.
What does a ‘molecular formula’ show?
Name the diatomic elements.
Write the correct formulas for covalent compounds such as: dihydrogen oxide, nitrogen trioxide, oxygen
diflouride, nitrogen monoxide, carbon tetrachloride, uranium hexaflouride.
Write the correct chemical names for compounds such as: MnB5, Na3PO4, Na2HPO4, (NH4)2PO4, NH4FeSO4,
Ti2O3, NH3
A catalyst is ____________________________.
Describe the five basic types of chemical reactions (with appropriate examples).
Which type(s) of chemical reactions produce heat? And what is distinctive about them?
Which type(s) of chemical reactions only involve ions? Give examples
Write the symbol for the ion and the number of electrons it contains for: magnesium, fluorine, oxygen,
iron (III), lead (IV), and copper (I).
Write the ion formula for: cuprous, cupric, ferrous, ferric, plumbous, plumbic, stannous, stannic.
In every balanced chemical equation, each side of the equation has the same number of _______.
In every chemical reaction, ______________________ is ______________________.
In a chemical reaction the mass of the products is __________________________ the mass of the reactants.
BALANCE MOST OF THE FOLLOWING CHEMICAL REACTIONS
____ H2 + ____ O2  ____ H2O
____ LiNO3 + ____ CaBr2  ____ Ca(NO3)2 + ____ LiBr
____ Si(OH)4 + ____ NaBr  ____ SiBr4 + ____ NaOH
____ LiCl + ____ Br2  ____ LiBr + ____ Cl2
____ NaCN + ____ CuCO3  ____ Na2CO3 + ____ Cu(CN)2
____ P4 + ____ O2  ____ P2O3
____ NaF + ____ Br2  ____ NaBr + ____ F2
____ AlBr3 + ____ K2SO4  ____ KBr + ____ Al2(SO4)3
____ K + ____ Cl2  ____ KCl
____ NH3 + ____ H2SO4  ____ (NH4)2SO4
_____ H3BO3  _____ H4B6O11 + _____ H2O
_____ H3AsO4  _____ As2O5 + _____ H2O
_____ C7H16 + _____ O2  _____ CO2 + _____ H2O
_____ Fe + _____ H2O  _____ Fe3O4 + _____ H2
_____ Mg + _____ N2  _____ Mg3N2
_____ Ca3(PO4)2 + _____ SiO2  _____ P4O10 + _____ CaSiO3
BALANCE MOST OF THE FOLLOWING CHEMICAL REACTIONS
____ H2 + ____ O2  ____ H2O
____ LiNO3 + ____ CaBr2  ____ Ca(NO3)2 + ____ LiBr
____ Si(OH)4 + ____ NaBr  ____ SiBr4 + ____ NaOH
____ LiCl + ____ Br2  ____ LiBr + ____ Cl2
____ NaCN + ____ CuCO3  ____ Na2CO3 + ____ Cu(CN)2
____ P4 + ____ O2  ____ P2O3
____ NaF + ____ Br2  ____ NaBr + ____ F2
____ AlBr3 + ____ K2SO4  ____ KBr + ____ Al2(SO4)3
____ K + ____ Cl2  ____ KCl
____ NH3 + ____ H2SO4  ____ (NH4)2SO4
_____ H3BO3  _____ H4B6O11 + _____ H2O
_____ H3AsO4  _____ As2O5 + _____ H2O
_____ C7H16 + _____ O2  _____ CO2 + _____ H2O
_____ Fe + _____ H2O  _____ Fe3O4 + _____ H2
_____ Mg + _____ N2  _____ Mg3N2
_____ Ca3(PO4)2 + _____ SiO2  _____ P4O10 + _____ CaSiO3