

Stoichiometry: Objectives: 1. Define stiochiometry and describe its significance. 2. Explain the relationship between stoichiometry and balanced chemical equations. Web Resources: (sphs.spusd.net/groves/ images/dert.gif) Stoichiometry: Stoichiometry is simply the measurement of reactants and products in a balanced equation. As was stated earlier in this semester, mass is conserved in any balanced equation. Therefore, we should be able to predict the quantity and mass of products from known reactants in any equation using stiochiometric relationships. Interpreting balanced equations: Mole  Mole Conversions CH_{4} + 2O_{2} g CO_{2} + 2H_{2}O
Consider the balanced equation above. Reactants:
Products:
Stoichiometry is just like reading a recipe and should be approached the same way. The above recipe calls for 1 part methane to be mixed with 2 parts oxygen to produce 1 part carbon dioxide and 2 parts water.
How moles of methane would you mix with 10 moles O? (remember that the mole ratio is 2:1) A. 2.5 B. 5 C. 10 D. 20 (answer is at the bottom) Math solution: 10 mol O x 1mol CH_{4} / 4 mol O = ? How many moles of CO_{2} would this produce? A. 2.5 B. 5 C. 10 D. 20 (answer is at the bottom) Math solution: 10 mol O x 1mol CO_{2} / 4 mol O = ? How many moles of H_{2}O would this produce? A. 2.5 B. 5 C. 10 D. 20 (answer is at the bottom) Math solution: 10 mol O x 2mol H_{2}O / 4 mol O = ? How would the problem be different if you started with 10 moles O2?
answers: A, A, B, all quantities would be doubled.

Last modified: January 26, 2004 