Chemistry: would someone verify my work, please?

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Discussion Overview

The discussion revolves around a homework problem involving the calculation of nitrogen percentage by mass in coal and the mass of nitrogen produced as NO when coal is burned. The scope includes mathematical reasoning and verification of calculations related to chemistry.

Discussion Character

  • Homework-related
  • Mathematical reasoning

Main Points Raised

  • The initial calculation for the percent of nitrogen by mass in coal is presented, with a resulting value of 0.734% based on the molar masses of the components of coal.
  • The participant calculates the mass of NO produced from burning three tons of coal, arriving at 42.8 kg, and questions whether this figure includes both nitrogen and oxygen.
  • One participant confirms the mass of NO calculated and prompts consideration of the mass percentage of nitrogen in NO.
  • Another participant clarifies that the question specifically asks for the mass of NO, not just nitrogen, suggesting the participant should express the result in tons or pounds for completeness.

Areas of Agreement / Disagreement

There is no consensus on the interpretation of the results, particularly regarding the distinction between the mass of NO and the mass of nitrogen within it. Some participants confirm the calculations while others seek clarification on the specifics of the question.

Contextual Notes

Participants express uncertainty about whether the calculated mass of NO includes both nitrogen and oxygen, highlighting a potential misunderstanding of the question's requirements.

Who May Find This Useful

Students working on chemistry problems involving stoichiometry and combustion reactions, as well as those seeking to verify their calculations in similar contexts.

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Homework Statement



Assume that coal can be represented by the formula C135H96O9NS. A. What is the percent of nitrogen by mass in this coal? B. If three tons of coal were burned completely, what mass of nitrogen in NO would be produced? (Assume that all of the nitrogen in the coal is converted to NO in the burning process.) Be sure to show all your calculation work in each case.

The Attempt at a Solution



A.135x12.01=1621.35 (carbon) + 96x1.008=96.76 (hydrogen) + 9x16.00=144 (oxygen) + 1x14.01=14.01 (nitrogen) + 1x32.07=32.07 (sulfur) = 1908.19. 14.01x100/1908.19= 0.734%.

B.First, to find the moles of coal in 6000lbs of coal, I converted the pounds to grams and divided it by the mole weight (6000 x 453.6 / 1908.19 = 1426.27). Since one mole of coal provides one mole of NO, there are 1426 moles of coal and 1426 moles of Nitrogen. NO has a molar mass of 30g/mol, so 30g/mol x 1426 moles = 42.8kg of NO. Therefore, the mass of nitrogen in NO that would be produced when three tons of coal is burned completely is 42kg. (Am I including both nitrogen and oxygen in this figure? I'm only suppose to be looking for nitrogen??)

I want to make sure I have done this right. If not, please point me in the right direction:)
 
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So you've got 42.8 kg of NO. They want to know how much of this is nitrogen.
 
Is 42.8kg the correct number of NO? Is there a formula to use to find how much of this is N?
 
I've checked your work and it seems that that is the correct answer.

Think about 1 mol of NO. What percent of this (in terms of mass) is nitrogen?
 
The question asks you for the mass of NO, not N. Relax, you have it. You might want to express it in either tons or pounds for completeness.
 

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