Stoichiometry, inxs

Stoichiometry, INXS

Some important points to consider when dealing with stoichiometric calcualtions:

1. 
   Reactions are spontaneous. That is, when two chemicals are mixed, then they will actually react.
   

2. 
   The reaction is fast.
   

3. 
   The reaction goes to completion.
   

4. 
   The reaction is stoichiometric. The reactants and products react, in a simple whole number relationship.
   

Stoichiometry with a reactant in Excess Quantity.
Example:

5.0 g of oxygen and hydrogen are mixed. A spark caused an exothermic reaction to produce water. Determine how much water was produced in this reaction.

Example:

a) What mass of CS₂ is produced when 17.0 g of C are reacted with 39.5 g of SO₂?

5C + 2 SO₂ ---- CS₂ + 4 CO

b) What mass of the excess reactant will be left over?

Example:

A double replacement reaction takes place when 0.50 L of 0.20 M of sodium chloride is mixed with 0.50 L of 0.50 M Lead II nitrate. Which reactant is in excess? Calculate the moles of lead II chloride produced from this reaction.