Google Answers Logo
View Question
 
Q: chemistry ( Answered 5 out of 5 stars,   0 Comments )
Question  
Subject: chemistry
Category: Science > Chemistry
Asked by: teatea-ga
List Price: $3.00
Posted: 14 Jul 2003 21:10 PDT
Expires: 13 Aug 2003 21:10 PDT
Question ID: 231111
Ethane gas, C2H6, burns in air and produces carbon dioxide and water vapor.
a. Write a balanced equation for this reaction
b. If 15.0 liters of ethane are burned at STP, how many liters of CO2 are formed?
c. How many grams of water vapor are formed if 15.0 liters of ethane are burned?
Answer  
Subject: Re: chemistry
Answered By: livioflores-ga on 14 Jul 2003 22:44 PDT
Rated:5 out of 5 stars
 
Hi again!!

a. The balanced equation is (the combustion in air means a reaction
with O2):

 2 C2H6 + 7 O2 ---> 4 CO2 + 6 H2O


b. At STP one mol of gas has 22.4 L, then at STP 15 L will be
(15/22.4)= 0.67 moles, then we have 0.67 moles of ethane.

If the combustion of 2 moles of ethane produces 4 moles of CO2, the
combustion of 0.67 moles of ethane will produce (0.67*4/2) = 1.34
moles of CO2.

This 1.34 moles of CO2 will have (1.34*22.4 L) = 30 L

30 L of CO2 are formed by the combustion of 15 L of C2H6.


c. NOTE: You do not specify the conditions for this point, but I will
work using STP condition, if the condition is other, let me know by a
request of a clarification and I will gladly recalculate this problem
for you.

Again there are 0.67 moles of ethane reacting and for every 2 moles of
C2H6 burned, 6 moles of water vapor are produced, then for this 0.67
moles of ethane burned we will obtain (0.67*6/2) = 2 moles of H2O.

The molecular mass of the water is (2*1g + 16g) = 18g and this is the
weight of one mol in grams, then we will have (2*18g) = 36g of H2O
from the combustion of 15 L of C2H6.


Note: you can find the following balanced equation of the combustion
of ethane in air:
  C2H6 + 3.5 O2 —-> 2 CO2 + 3 H2O
This reduction of a one mol of C2H6 is doing to simplify calculations
related to this combustion, wich is very important in industry for
example; see the following document from TeraSen Gas for reference:
"Natural Gas Characteristics and Combustion":
http://www.terasen.com/NR/rdonlyres/emc2qcljixzbh2e7c6qhjiytp6aaur5jcy7rgkllk2hl7q4inbsdwiuzearzv6wubi5fz6kspgimiualockqna4qrgb/NaturalGasCharacteristicsandCombustion.pdf


I hope this helps you. Please feel free for request for all the
clarifications needed.

Regards.
livioflores-ga
teatea-ga rated this answer:5 out of 5 stars

Comments  
There are no comments at this time.

Important Disclaimer: Answers and comments provided on Google Answers are general information, and are not intended to substitute for informed professional medical, psychiatric, psychological, tax, legal, investment, accounting, or other professional advice. Google does not endorse, and expressly disclaims liability for any product, manufacturer, distributor, service or service provider mentioned or any opinion expressed in answers or comments. Please read carefully the Google Answers Terms of Service.

If you feel that you have found inappropriate content, please let us know by emailing us at answers-support@google.com with the question ID listed above. Thank you.
Search Google Answers for
Google Answers  


Google Home - Answers FAQ - Terms of Service - Privacy Policy