• Make sure you balance every reaction before going the calculation.

  • I could not make the numbers after elements small. For example, for H2O, the “2” should be small. Please remember this.

  • I could not make the “=” sign arrows, but they are meant to be arrows.

Draw the 3D drawings for these molecules








Draw Lewis dot drawings for these molecules








Use electronegativity values to calculate the type of bond in these molecules










If these percentages come out of the machine used, what is the true (accurate) formula? If you cannot work out what order to write the atoms in, do some research on the internet.


49.48 % Carbon

5.19 % Hydrogen

16.14 % Oxygen

28.85 % Nitrogen

194.19 g/mol


86.88 % Carbon

13.12 % Hydrogen

345 g/mol


Three (only empirical formula)

38.8 % Carbon

16.2 % Hydrogen

45.1% Nitrogen


Four (only empirical formula)

88.45 % Boron

The rest is Hydrogen

Give me the products of these five common reactions


Na + Cl2 =

C + O2 =

4Fe + 3O2 =


H2O =


H2O2 = H2O +

Single displacement

Zn + CuSO4 =

Double displacement

BaCl2 + Na2SO4 =

Combustion reaction

C3H8 + O2 =

There are many different kinds of reactions. Two types we call physical and chemical. Using this information, work out if these reactions are physical or chemical AND explain why you chose it.


A reaction produces a new smell.


A reaction produces a gas and heat, but there is no color change and no new smell and no flame.


A reaction creates a new color, but no new smell. No gas is produces but the temperature changes.

Name these molecules












Using known bond energies, calculate the heat of these reactions. Are they endo or exo or Iso – thermic?

 C3H8 + O2   =       CO2 + H2O

H2O     =      H2 + O2

N2 + O2     =       NO

H2    =        H

CH4 + Cl2      =        CCl4 + HCL

Work out these Stoichiometric problems.

1.) HgO = Hg + O2

If 200 g of Hg and 16 g of O2 is produced, what was the mass in grams of HgO that we had at the start?

2.) You are a geologist and you dig up a mass of rock with mass 95 g. You do some experiments and this sample contains 70 % Sodium. What is the mass of pure Sodium in this sample. Your final answer must be in Kg.

3.) If 10 g of KCl dissolves in 200 ml of H20. What is the weigh % of KCl in the solution? The density of H20 is 1 g/ml.

4.) Ca(OH)2 + HCl  =   CaCl2 + H2O

If 150 g of Calcium Hydroxide, with a Molecular (molar) mass of 75 g/mol. How many moles of HCl will it react with?

5.) C6H12O6 =  C2H5OH + CO2

If 360 g of C6H12O6 decomposes and makes CO2 gas, what will the mass in grams of CO2 be?

6.) 75.0 g of Mg and 75.0 g of Cl2 are placed in a beaker and they react like this:

Mg + Cl2 = MgCl2

  • Which substance is the limiting reagent?

  • How many grams of the excess reactant remain?

  • What is theoretical ield in grams of MgCl2?

  • If 72.0 g of product are actually formed – what is the percentage yield of MgCl2?

7.) 25.0 g of P and 75.0 g of F2 react according to this:

2P + 5F2 = 2PF5

  • Which substance is the limitng reagent?

  • How many grams of the excess reactant ramin?

  • What is the theoretical yield in grams of PF5?

  • If 41.e g of the product is actualy formed, what is the percentage yield?

8.) If Na2S2O3 + AgBr = NaBr + Na3[Ag(S2O3)2]

  • How many moles of Na2S2O3 are needed to react completely with 42.7 g of AgBr

  • What is the mass of NaBr that wll be produced from 42.7 g of AgBr?

Equilibrium. (Examples taken from another website)

1.) An equilibrium constant with a value K > 1 means:

a. there are more reactants than products at equilibrium
b. there are more products than reactants at equilibrium
c. there are the same amount of products and reactants at equilibrium
d. the reaction is not at equilibrium

2.) Equal amounts of reactants are poured into a suitable container. Given sufficient time, the reactants may be converted almost entirely to products if:

a. K is less than 1
b. K is greater than 1
c. K is equal to 1
d. K is equal to 0


H2 (g) + I2 (g) ↔ 2 HI (g)

would be:
a. K = [HI]2/[H2][I2]

b. K = [H2][I2]/[HI]2

c. K = 2[HI]/[H2][I2]

d. K = [H2][I2]/2[HI]

4.) The equilibrium constant for the reaction

2 SO2 (g) + O2 (g) ↔ 2 SO3 (g)

would be:
a. K = 2[SO3]/2[SO2][O2]

b. K = 2[SO2][O2]/[SO3]

c. K = [SO3]2/[SO2]2[O2]

d. K = [SO2]2[O2]/[SO3]2

5.) The equilibrium constant for the reaction

Ca(HCO3)2 (s) ↔ CaO (s) + 2 CO2 (g) + H2O (g)

would be:
a. K = [CaO][CO2]2[H2O]/[Ca(HCO3)2]

b. K = [Ca(HCO3)2]/[CaO][CO2]2[H2O]

c. K = [CO2]2

d. K = [CO2]2[H2O]

6.) The equilibrium constant for the reaction

SnO2 (s) + 2 H2 (g) ↔ Sn (s) + 2 H2O (g)

would be:
a. K = [H2O]2/[H2]2

b. K = [Sn][H2O]2/[SnO][H2]2

c. K = [SnO][H2]2/[Sn][H2O]2

d. K = [H2]2/[H2O]2

7.) For the reaction

H2 (g) + Br2 (g) ↔ 2 HBr (g),

K = 4.0 x 10-2. For the reaction

2 HBr (g) ↔ H2 (g) + Br2 (g)

K =:
a. 4.0 x 10-2
b. 5
c. 25
d. 2.0 x 10-1

8.) At a certain temperature, K = 1 for the reaction

2 HCl (g) → H2 (g) + Cl2 (g)

At equilibrium, you can be certain that:
a. [H2] = [Cl2]

b. [HCl] = 2[H2]

c. [HCl] = [H2] = [Cl2] = 1

d. [H2][Cl2]/[HCl]2 = 1

9.) For the reaction: A + B ↔ C + D

6.0 moles of A and 5.0 moles of B are mixed together in a suitable container. When equilibrium is reached, 4.0 moles of C are produced.

The equilibrium constant for this reaction is:
a. K = 1/8
b. K = 8
c. K = 30/16
d. K = 16/30

10.) The Haber process is a method to produce ammonia from hydrogen and nitrogen gasses. The reaction is

N2 (g) + 3 H2 (g) ↔ 2 NH3 (g)

If hydrogen gas is added after the reaction has reached equilibrium, the reaction will:
a. shift to the right to produce more product
b. shift to the left to produce more reactants
c. stop. All the nitrogen gas has already been used up.
d. Need more information.


1. b. there are more products than reactants at equilibrium
2. b. K is greater than 1

3. a. K = [HI]2/[H2][I2]

4. c. K = [SO3]2/[SO2]2[O2]

5. d. K = [CO2]2[H2O]

6. a. K = [H2O]2/[H2]2

7. c. 25

8. d. [H2][Cl2]/[HCl]2 = 1

9. b. K = 8

10. a. shift to the right to produce more product


Go to this link to practice.

Organic chemistry.

Go to these links to practice.