Midterm Solution

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Chloe Orsini 1K
Posts: 32
Joined: Fri Sep 28, 2018 12:18 am

Midterm Solution

Postby Chloe Orsini 1K » Sat Dec 08, 2018 9:56 am

I am looking at question number two on the midterm and I am confused by the solution. For the ratios it says they are 1.4:1.2:1
To get 1.4 you divide the moles of co2 by the moles of o2
But to get 1.2 you have to divide the grams of H2O by the moles of O2

Why would you do this?

Yousif Jafar 1G
Posts: 59
Joined: Thu May 10, 2018 3:00 am

Re: Midterm Solution

Postby Yousif Jafar 1G » Sat Dec 08, 2018 10:18 am

for that question the ratios are not derived from the overall molecules. What you have to do is find the moles of C in CO2, the moles of H in H2O and then add those two together. This number will be subtracted from 1 because that is the weight of your unknown compound, giving you the grams of O which you can turn into moles. From there you divide each by the smallest number leading to the ratio of 1.4:1.2:1

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