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**Try some
practice worksheets**

Remember that at the beginning of the year, we did a lab where we added baking soda to vinegar and collected the whole mess in a rubber glove? Well, most of you were able to show that the mass of the stuff that we made was the same as the mass of the stuff we started with. (If you weren't one of those lucky people, then let me be the first to tell you this: The mass of the stuff that you make in a chemical reaction is the same as the mass of the stuff that you start with). This is called the Law of Conservation of Mass. Now, this shouldn't really be all that surprising, considering that this is true for most everything else in life. For example, when I make my world-famous chili, the weight of the chili that I make is the same as the weight of all the ingredients added together. As it is with chili, so it is with chemical reactions. Now, when we write chemical equations, we need to have the formulas for the reagents on the left side (the stuff that's going to do the chemical reaction) and the formulas for the products (the stuff you make) on the right. If we were to simply put the formulas of the chemicals on the left and right without saying how much of it was going to react, then we would run the risk of saying that the mass of what we end up with is different than the mass of what we started with. This would be the same thing as writing a recipe where we didn't specify how much of each ingredient is needed to make the chili. The bottom line: You need to balance the equations by sticking numbers in front of the chemicals on the left and right sides of the equation, like it or not. How can you do this? Check out the next section, titled... |

OK. You know why you need to balance chemical equations, but you don't yet know how to do it. It turns out that I'm star who knows how to explain things in a way that even the dumbest people know how to follow. And, hey, if the dumbest people can figure it out, so can you! Listen: There are four easy steps that you need to follow to make this work. Here they are:
Read on for an example... |

Let's say I ask you the following thing on a test: "Balance the equation that takes place when sodium hydroxide reacts with sulfuric acid to form sodium sulfate and water." How do we solve this using the steps above?
Well, we can see that on the left side of
the inventory, there is one atom of sodium and on the right there are two.
The solution: Stick a " Now what? Well, looking at the new inventory, we can see that we now have two sodium atoms on both the left and the right sides, but the others still don't match up. What to do? You can see from the inventory that on the
right side of the equation, there are two hydrogen atoms and on the left
there are four. Using your amazing powers of mathematics (and hopefully not
needing to use a calculator), you can see that two multiplied by the number
two becomes four. That's what you need to do. How? Put a " Since both sides of the inventory match, the equation is now balanced! All other equations will balance in exactly the same way, though it might take a few more steps in some cases. |

Is it all as easy as I made it look above? Well, yes and no. Yes, it should work all the time. No, sometimes you need to do some tricks to find the right numbers to add into the equation. For example, what happens when you do the inventory, and you find that there are two atoms of element X on the left side of the equation and three on the right. How can you make those match? When you run into this problem, find the
lowest common denominator of those two numbers, and then put the numbers in
front of those two boxes which allow the inventory on both sides to match. In
the element X example, the lowest common denominator of two and three is six,
so you'd put a " Another common problem: What happens when the only way you can get a problem to work out is to make one of the numbers a decimal or fraction? When this happens, find the largest
molecule in the equation and stick a " Most importantly: |

Here are some practice problems. The solutions are in the section below this one. 1. __NaCl + __BeF 2. __FeCl 3. __AgNO 4. __CH 5. __Mg + __Mn |

1. 2 NaCl + 1 BeF 2. 2 FeCl 3. 1 AgNO 4. 1 CH 5. 3 Mg + 1 Mn |