0.200mol of a hydrocarbon undergo complete combustion to give 35.2g of carbon dioxide and 14.4g of water as the only products. What is the molecular formula of the hydrocarbon? (C = 12.0, H = 1.0, O = 16.0). Please help with this sir
Hey Daniel! Start by focussing on the amount of CO2 and H2O produced. We want to know how many moles of Carbon and Hydrogen atoms are in the original compound to find its formula. So using the molar mass of CO2 and H2O respectively, figure out the moles of each compound, then how many grams of Carbon and Hydrogen you have in the 2 products. You can then figure out the mole ratio of Carbon to Hydrogen which will give you the empirical formula. Good Luck!
Assuming mass = 100g makes it easier because we are given percentages which is out of 100, so we can just use the percent values without doing any conversion.
11:36 And sir i got lost when you said when if the number of moles of one if the elements is in like 1.3 then you multiply by three. Why is that and what if it’s in like 1.4 or 1.7, what happens then?
Sorry to disturb you sir but i came across this question and it seems confusing now: A compound is found to contain 32.65% of carbon, 13.04% of Hydrogen and 54.31 % of oxygen. Determine the empirical formula
The video helped me a lot in understanding the concept. Thank you very much
You're welcome - thanks for saying so!
I recommend this channel to all my friends now they all passing their exa,
Thank you, Maryam H.
This video helped me a lot! Thanks Chad. I also like the shirts you wear in your lessons.
Glad to hear it, DauntlessK!
Your videos are helping me a lot to study and review for my AP Chem final! Thank you!
You're welcome - hope you crush the final!
Love the Shirt!
Excellent!
0.200mol of a hydrocarbon undergo complete combustion to give 35.2g of carbon dioxide and 14.4g of water as the only products. What is the molecular formula of the hydrocarbon? (C = 12.0, H = 1.0, O = 16.0). Please help with this sir
Hey Daniel! Start by focussing on the amount of CO2 and H2O produced. We want to know how many moles of Carbon and Hydrogen atoms are in the original compound to find its formula. So using the molar mass of CO2 and H2O respectively, figure out the moles of each compound, then how many grams of Carbon and Hydrogen you have in the 2 products. You can then figure out the mole ratio of Carbon to Hydrogen which will give you the empirical formula. Good Luck!
I'm confused, why times 100, not 100%. 12/100*100 should be 12 not 12%, is that true?
If u don't take x100, you get the answer in decimals. Take the number times 100 and u will get the %.
I get it. You mean take times 100, then plus a % symbol, I mean just take times 100%, they are same things.
@@scottfeng9150 yes, add the% sign
Sir is it always going to be the case to assume a mass of 100g of the compound when it’s not being given in the question?
And please specify why it’s a mole to mole ratio and not atom to atom ratio. I understand why it’s not a gram to gram ratio though
Assuming mass = 100g makes it easier because we are given percentages which is out of 100, so we can just use the percent values without doing any conversion.
11:36 And sir i got lost when you said when if the number of moles of one if the elements is in like 1.3 then you multiply by three. Why is that and what if it’s in like 1.4 or 1.7, what happens then?
Sorry to disturb you sir but i came across this question and it seems confusing now: A compound is found to contain 32.65% of carbon, 13.04% of Hydrogen and 54.31 % of oxygen. Determine the empirical formula
Hi, do you have problem solving videos for those calculations
Which calculations in the video? I go through a few different calculation examples
@@ChadsPrep i mean examples to find empirical and molecular formulas