What Is the Correct Theoretical Yield of HNO3 in This Chemistry Problem?

In summary, the book has a typo in the question and the answer given is on grams of NO2 produced, not on theoretical yield of HNO3.
  • #1
ducmod
86
0

Homework Statement


Hello!
I would be grateful for your help on finding my mistake - somehow my answers are
wrong compared to the answer from the book.
Here is the exercise from a paragraph on gases (cumulative gas law, basics):

Consider the reaction for the synthesis of nitric acid:
3NO2 + H2O = 2HNO3 + NO
(a) If 12.8 L of NO2 measured at STP, is allowed
to react with 14.9 g of water, find the limiting
reagent and the theoretical yield of HNO3 in
grams.

Here is my solution:

1 mole of gas at STP = 22.4 L; 12.8 L gives 0.5714 moles of NO2
1 mole of H2O = 18.016 g; 14.9 g = 0.827 moles of H2O

The limiting reagent is NO2, because
3 moles NO2 + 2 moles of H2O
0.5714 moles NO2 requires only 0.381 moles of H2O, but we have 0.827 moles of H2O

1 mole of NO2 = 46.007 g
0.5714 moles of NO2 = 26.288 g
Theoretical yield of HNO3:
3 moles of NO2 = 2 moles of HNO3
0.5714 moles of NO2 = 0.3809 moles of HNO3

1 mole of HNO3 = 63.008
0.3809 moles of HNO3 = 24.001 g

Thank you!
 
Physics news on Phys.org
  • #2
ducmod said:
3 moles NO2 + 2 moles of H2O
Why 2 moles of H2O?
The conclusion is still right.

Looks right.
I don't think you have to work with decimal numbers of molar masses, they are very close to integers for the involved elements.
 
  • #3
There is the mistake mfb already pointed out, but it doesn't influence the final answer.

What is the answer given in the book?
 
  • #4
mfb said:
Why 2 moles of H2O?
The conclusion is still right.

Looks right.
I don't think you have to work with decimal numbers of molar masses, they are very close to integers for the involved elements.
Thank you! Sorry, yes, only one mole of H2O.
 
  • #5
Borek said:
There is the mistake mfb already pointed out, but it doesn't influence the final answer.

What is the answer given in the book?
I think the problem was in the question - there is some typo in the book, because exercise is asking about theoretical yield of HNO3,
while the book gives answer on grams of NO2
 

1. What happens to gases during exercise?

During exercise, the body's demand for oxygen increases. As a result, the respiratory system works harder to bring in more oxygen and expel carbon dioxide. This leads to an increase in breathing rate and volume, causing the body to take in more oxygen and release more carbon dioxide. This process is known as ventilation and is essential for the body to maintain its oxygen supply during physical activity.

2. How does exercise affect the amount of gases in our blood?

During exercise, the body produces more carbon dioxide due to increased metabolic activity. This leads to a decrease in blood pH, which is regulated by the respiratory system through an increase in breathing rate. The increased breathing rate helps to remove excess carbon dioxide from the blood and maintain a balance of gases in the body.

3. Can exercise help with gas exchange in the lungs?

Yes, exercise can help improve gas exchange in the lungs. Regular physical activity helps to strengthen the respiratory muscles, making them more efficient at taking in oxygen and expelling carbon dioxide. Exercise also increases blood flow to the lungs, allowing for better distribution of oxygen throughout the body.

4. How do gases play a role in regulating body temperature during exercise?

During exercise, the body produces heat as a byproduct of metabolism. To maintain a stable body temperature, the body uses sweat to release heat from the skin and cool the body. The respiratory system also plays a role in regulating body temperature by releasing excess heat through the exhalation of warm, moist air.

5. How does the body adjust to high altitudes during exercise?

At higher altitudes, the air pressure decreases, resulting in a decrease in the amount of oxygen available for the body to use. To compensate for this, the body increases its breathing rate and volume to bring in more oxygen. This process can take a few days to adjust to, and during this time, the body may experience symptoms such as shortness of breath, fatigue, and dizziness. However, with regular physical activity at high altitudes, the body can adapt and become more efficient at utilizing oxygen.

Back
Top