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Sunday, November 14, 2010
Ch 12_1 #4
Calculate molecular mass of H2O2 then calculate number of moles
4 comments:
Anonymous
said...
How do you figure out the number of atoms if you're given grams?
I got the molecular weight of H2O2, which is 34.016grams per mole, and then I found the number of moles of H2O2 in 140 grams of it, which was 4.11 moles. Now I got either 2.5*10^24 atoms, total, or 1.24 atoms of hydrogen. But it's telling me I'm wrong!!! =(
I am not sure how you got 1.24 atoms of hydrogen, do you mean 1.24*10^24? Which would imply that you divide 2.5/2. Why? 2.5 is number of H2O2 molecules, but you have to find number of H (you have two of them per H2O2 molecule)
4 comments:
How do you figure out the number of atoms if you're given grams?
You know how many atoms in a mole. Find how many moles you have then you can figure out number of atoms. We did in workshop today.
I got the molecular weight of H2O2, which is 34.016grams per mole, and then I found the number of moles of H2O2 in 140 grams of it, which was 4.11 moles. Now I got either 2.5*10^24 atoms, total, or 1.24 atoms of hydrogen. But it's telling me I'm wrong!!! =(
I am not sure how you got 1.24 atoms of hydrogen, do you mean 1.24*10^24?
Which would imply that you divide 2.5/2. Why? 2.5 is number of H2O2 molecules, but you have to find number of H (you have two of them per H2O2 molecule)
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