Posted by **Marius** on Wednesday, October 4, 2006 at 1:23pm.

2Fe + 3Cl2 -> 2FeCl3

How much FeCl3 can you produce with 10g of Fe and how much Cl2 will be consumed?

The chain of thought in my head is, first calculate the amount of mol in Fe, done by taking the mass over the molarmass

10g/55,85 = 0,179mol

If this is the amount of Fe mol, then, I think, the amount of FeCl3 can't be of a higher mol, because of the limiting involved by the amount of Fe. If I take the 0,179mol and multiply it with the molarmass of FeCl3, I get around 29g, which is 10g too much.

Any ideas?

Thank you for posting your work. The 0.179 mol Fe is correct. Two mols Fe will produce 2 mols FeCl3; therefore, 0.179 mol Fe will produce 0.179 x 162.2 g FeCl3/mol FeCl3 = 29.03 g FeCl3. Why do you think that is 10 g too much? I don't see anything wrong with your thinking or your calculations.

For some odd reason my teacher wrote 19,05g and me and my friend have been picking our brains to try and make it fit. Thanks for clearing it up Dr.Bob =)

I'm sure your teacher just made a typo (or a hando if written by hand) for your thinking and your calculations are absolutely correct. And we are glad to be of service. Feel free to post anytime.

16

i can't figure out how to convert fractions to decimals. and percents to fractions

Let's start with percents to fractions:

Per cent literally means per hundred. If you're talking 50%, you can write that as 50/100, which simplifies into 1/2. If you have 300%, you have 300/100, or 3.

Fractions to decimals are a little bit trickier. Take the top number (the numerator) and divide by the bottom number (the denominator). 2/5 would be read the same as 2 divided by five. When you do the long division, you get .4

Hope that helps!

Amy :)