When cooking, it's frequently handy to predict what will happen when we mix a bunch of ingredients together. For example, if we're interested in making a delicious new salad dressing, we would have a very small chance of making anything edible if we had no way of knowing which ingredients would have the greatest chance of succeeding.
Likewise, it's often necessary for chemists to predict the chemical reactions that will take place when two chemicals are combined. For example, if we're adding a chemical to a tank of toxic waste to stabilize it, we'd be very unhappy if we failed to predict an explosive reaction.
The tips in this section, while helping you to figure out what reaction might occur, aren't infallible in correctly predicting the reaction that will take place. However, if you're not sure what will happen, these tips will be useful in suggesting some possibilities.
An easy way to predict what reaction will take place when two chemicals are mixed is to identify the type of reaction that's likely to occur when the chemicals are combined. Of course, we mentioned before that these types of reaction are arbitrary, but they do sometimes have a useful purpose.
There are two common mistakes when predicting the products of a chemical reaction. The first is predicting the formation of a theoretically impossible product such as NaCO3 or Ag4Cl. The second is failing to balance the equation once the products have been accurately predicted
Here are some tips you may find handy in helping to predict the type of reaction that will occur if you know only the reactants. Keep in mind that not all combiations of chemicals will result in a chemical reaction—these tips are handy only for helping to predict what would happen should they happen to react.
Problem 4: Write balanced chemical equations for the reactions that might occur when the following reactants are combined:
a) NaOH + H2 SO4 ⇔ ?
b) NH3 + I2 ⇔ ?
c) C3H8O + O2 ⇔ ?
Excerpted from The Complete Idiot's Guide to Chemistry © 2003 by Ian Guch. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.