× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
t
7
m
6
k
6
F
5
j
5
t
5
j
5
G
5
f
5
a
5
d
5
c
5
New Topic  
fioravme09 fioravme09
wrote...
Posts: 53
Rep: 1 0
11 years ago
A certain compound, is known to contain carbon and hydrogen. It might also contain oxygen.   A   4.226 g   sample of this compound was burned in pure oxygen gas. The measured amount of   CO2   produced was   8.074 g,   while that of   H2O   was   4.958 g.   No other products were produced in the reaction.

2.202 grams of carbon were in the original sample and 0.5509 grams of hydrogen were in the original sample.

What is the empirical formula?!!
Please help.
Ohh! I understand now!
Thank you! Smiling Face with Open Mouth
Read 454 times
1 Reply

Related Topics

Replies
wrote...
11 years ago
Your sample definately contains Oxygen.

The law of conservation of mass tells us that there must be the same mass in the products as there were in the reactants.

The mass of C + mass H in you products = 2.202 g + 0.5509 g = 2.753 g
But you started with 4.226 g of compound, so the difference in mass must be Oxygen
mass O = 4.226 g - 2.202 - 0.5509 = 1.473 g Oxyygen in the compound

Now work out the moles of C, H and O that were in the sample

moles = mass / molar mass

moles C = 2.202 g / 12.01 g/mol = 0.1833 moles C
moles H = 0.5509 g / 1.008 g/mol = 0.5462 moles H
moles O = 1.473 g / 16.00 g/mol = 0.0921 moles O

Arrange the moles in a ratio format

moles C : moles H : moles O
= 0.1833 : 0.5462 : 0.0921

Divide each number by the smallest number in the ratio to get it into a whole number ratio.

C : H : O
(0.1833 / 0.0921) : (0.5462/0.0921) : (0.0921/0.0921)
= 2 : 6 : 1

Empirical formula
C2H6O
New Topic      
Explore
Post your homework questions and get free online help from our incredible volunteers
  1038 People Browsing
Related Images
  
 387
  
 322
  
 128
Your Opinion
Which industry do you think artificial intelligence (AI) will impact the most?
Votes: 378

Previous poll results: How often do you eat-out per week?