Calculate the moles of CO2 formed when
4.2 mol of C3H8 react with 20.6 mol O2. Answer in units of mol.
So, the balanced equation is C3H8 + 5 O2
==> 3 CO2 + 4 H2O . I thought the answer would be 12.36 mol, but when I type it in it's wrong. Please help!
My best educated guess is that you are reporting the number with more significant figures than you are allowed. I obtained 12.36 also, however, you're allowed only 2 s.f. (from the 4.2) so the 12.35 rounds to 12.4 mols. Try that. If that doesn't fix the problem let me know at this post.
......so the 12.36 rounds to 12.4 mols.
Thanks! The site actually asks for 5 s.f., and it's saying that I am wrong no matter what I am typing in... I will just have to ask my teacher about it tomorrow! Thanks again!
If you have posted the problem exactly as is then the 4.2 has two s.f. and the 20.6 has three s.f. and you will be allowed 2 in the answer. You would need 4.2000 and 20.600 to be able to use 5 s.f.
To calculate the moles of CO2 formed when 4.2 mol of C3H8 react with 20.6 mol O2, we need to use the balanced equation:
C3H8 + 5 O2 --> 3 CO2 + 4 H2O
From the balanced equation, we can see that 1 mol of C3H8 reacts to form 3 mol of CO2. Therefore, we need to determine how many moles of CO2 are formed from 4.2 mol of C3H8.
Using the mole ratio, we can set up the following calculation:
(4.2 mol C3H8) x (3 mol CO2 / 1 mol C3H8) = 12.6 mol CO2
So, the correct answer is 12.6 mol CO2, not 12.36 mol as you initially calculated.
It's possible that your answer was marked as wrong due to rounding errors while calculating or inputting the answer. Make sure to enter the answer as 12.6 mol instead of rounding it to 12.36 mol.