Feb. 25 Translating World Equations and Balancing equations

TRANSLATING WORD EQUATIONS

When you encounter a word equations, you must specify what state each chemical is in. These are what you use to specify what state the chemical is in:

s = Solid , l = Liquid , g = Gas , aq = Aqueous
In the equation "and" or "reacts with" means +
"react to," or "produce" means ------>

Now we can use this knowledge to write our equation from words. An example: calcium hydroxide and hydrochloric acid produce calcium chloride and water.
Ca(OH)₂ + HCl --> CaCl₂ + H₂O


The next step is to balance the equation *DONT FOREGET TO ADD THE STATES!!*:
 Ca(OH)_2(s) + 2 HCl_(l) --> CaCl_2(aq) + 2 H₂O<sub>(l)

Here is a video:</sub> 


BALANCING EQUATIONS

Remember back in science 9 the balancing equations worksheets? Weren't they fun?! Well now in Chemistry 11 we get to do them AGAIN!! That's right AGAIN!! In case you forgot how to do them or need some basic tips to do them, these are some steps/tips to do it:

1. Write the equation. This is just what will react; forget the coefficients for now. However, you do need to balance the charges. For example, if you were reacting copper(II) nitrate with Sodium, you would write:
Cu(NO₃)₂ + Na --> NaNO₃ + Cu

2.Determine how any atoms are on both sides of the equation. In the example, there is 1 copper atom, 2 nitrate ions, and 1 sodium atom being reacted. Meanwhile, there is 1 sodium ion, 1 nitrate ion, and 1 copper atom being produced.

3.Add coefficients to the element or ion that needs to be increased.  Since there is (NO₃)₂ on the left side, you will have to make the NO₃ the right side equal the left side's. You'll now have the following:
Cu(NO₃)₂ + Na --> 2NaNO₃ + Cu

4.Continue adding coefficients until you have the same amount of atoms on each side of the equation.  Since you added 2 to the NaNO₃ on the right side, there is 2 Na.  The left side has only 1 Na. You must make the Na on the right equal the Na on the left.  You would add 2 to the Na on the left side.  The final equation would be this:
Cu(NO₃)₂ + 2Na --> 2NaNO₃ + Cu

*Hint*
When balancing an partially unknown equation, start with the elements that are rarest, and finish with hydrogen and oxygen (which form water).

Here is a website with a bunch of documents on balancing chemical equations in pdf format:

http://misterguch.brinkster.net/july2000.pdf

Here is a video about balancing chemical equations: