<p>my ap chem teacher doesnt explain anything to the class and gives out homework on this workbook called the Ultimate Chemical Equations handbook.
We're supposed to predict/balance single replacement reactions and double replacement (metathesis) reactions.
even though i took an ap chem prep course, i didnt learn this stuff at all.
like one of the problems about the single-replacement reactions (predict and balance) is:
A piece of copper is dropped into a container of water.
And metathesis reaction (predict and balance)
Ammonium sulfate and potassium hydroxide are mixed together.
How do we know what to do in these kinds of problems? What is necessary to memorize to be good at these?</p>
<p>It is what it says... Single replacement and double replacement.
The first thing you need to do is to split everything into ions, which will make your life a lot easier. For single replacement Cu is a cation, and OH- is an anion, so CuOH and H2 will be formed.
For the 2nd one just split and up into cations/anions then switch cations/anions.</p>
<p>^ yeah. And, since you just learning this stuff, it would help if you write the skeletal formula for the reaction first, And then balance it.</p>
<p>1) skeletal: Cu + H20 > CuOH + H2
balanced: 2Cu + 2H20 > 2CuOH + H2</p>
<p>basically remember your cations (metals) and anions (non-metals), then it will become obvious as to what needs to be done. Covalent bonds aren't as straight foward, but you'll cross that bridge when you come to it. good luck</p>
<p><a href="http://www.geocities.com/crazytwo2000/%5B/url%5D">http://www.geocities.com/crazytwo2000/</a>
This website helped me a lot for rxn prediction. I know it might be a bit early to start practicing, but if you read the explanations for the answers, it explains a lot of what would happen and stuff.</p>