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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: xeomonk on September 26, 2008, 04:42:48 PM

Title: Consecutive Reactions
Post by: xeomonk on September 26, 2008, 04:42:48 PM

Hi I am having trouble in this problem.

What mass of melamine will be obtained from 145.5 kg of urea if the yield of the overall reaction is 81.0%?

First I calculated the number of kilomoles of urea

2.43 kmol 

After I figured out the ratio between urea and melamine

which is 6

Then I figure out the molar mass of melamine

which is 126.0  kg/kmol 

This is the part where I get stuck. I cannot figure out the next step to solving this problem.

Title: Re: Consecutive Reactions
Post by: Borek on September 26, 2008, 06:12:42 PM

What is the percentage yield definition? Write it and solve for the practical mass.