Chemists MUST be able to predict what happens in a chemical reaction. You never want to mix two compounds if you can't predict the outcome. It's a matter of safety.
Predicting Products of Single Replacement Reactions:
- Analyze the reactants to note the "lone element" and the compound. What element in the compound is similar to the "lone element?"
- Check the activity series to see if the "lone element" is higher than the "like element" in the compound.
- If so, then the lone element will take the place of the like element in the compound. You'll have to criss-cross to write the new compound formula.
- The element that was removed from the compound now becomes the lone element in the products.
Predicting Products of Double Replacement Reactions:
- Analyze the reactants to note the cation and anion in each compound. What were their original charges?
- Switch the cations in the compounds, and rewrite the new compounds. You'll have to criss-cross the new compounds.
- Remember, the cation should always be listed first in an equation.
Predicting Products of Combustion Reactions:
- Analyze the reactants. Are the reactants a hydrocarbon and oxygen gas?
- If so, then the reactants are carbon dioxide and water vapor.