[cloud5]

Correct me if I'm wrong. I think the red boxed is supposed to be (3-2.7). Am I right?

http://img217.imageshack.us/img217/1518/80033205.jpg

Here is the question.
http://img253.imageshack.us/img253/6669/17097368.jpg

[Cherriyan]

Yes, you are right! The red boxed value should be (3-2.7).
As far as the question is concerned, here is what you should do. Keep in mind that 1 mole of N₂ reacts with 3 moles of H₂ to form 2 moles of NH₃. Accordingly, calculate the no. of moles of N₂ reacting to form 1.8 moles of NH₃. Convert the no. of moles of N₂ (present originally, and the number remaining after the reaction) to grams, and using these values calculate the percentage of N₂ reacted. You will get the same answer as written in the image you have posted.

[cloud5]

Yes, you are right! The red boxed value should be (3-2.7).
As far as the question is concerned, here is what you should do. Keep in mind that 1 mole of N₂ reacts with 3 moles of H₂ to form 2 moles of NH₃. Accordingly, calculate the no. of moles of N₂ reacting to form 1.8 moles of NH₃. Convert the no. of moles of N₂ (present originally, and the number remaining after the reaction) to grams, and using these values calculate the percentage of N₂ reacted. You will get the same answer as written in the image you have posted.

Thanks a lot~

[Cherriyan]

You're welcomed!