Can someone tell me why this method is wrong even though it seems logical?

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In summary, the molar mass of LiOH is 23.949g/mol. To calculate the mass of gaseous carbon dioxide that can be absorbed by 1.00kg of LiOH, we use the equation 1000g LiOH x (12.01+32.0)g CO2 / 2(6.941+16.0+1.01)g LiOH. This gives us a result of 920g CO2. However, it is important to double check calculations to avoid making mistakes.
  • #1
lLovePhysics
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Homework Statement


Solid lithium hydroxide is used in space vehicles to remove exhaled carbon dioxide from the living environment by forming solid lithium carbonate and liquid water. What mass of gaseous carbon dioxide can be absorbed by 1.00kg of lithium hydroxide?



The Attempt at a Solution



First, I balanced out the equation with the reactants and products:

[tex]2LiOH+CO_2 \right arrow Li_{2}CO_{3}+H_{2}O[/tex]

Then I found the molar mass of LiHO to be: 23.949g/ mol LiHO

So then I did this:

[tex]\frac{23.949g}{mol \\LiHO} \times \frac{2mol LiHO}{1molCO_{2}}=\frac{47.898g}{1molCO_2} \times \frac{1molCO_2}{44.01g}[/tex]

Other than that the units cancel out.. can someone tell me why it is wrong and how to avoid these problems? As of now, I just try to cancel the units out to get grams but I don't really have a "systematic" way of doing things. Is there a a systematic way? How do avoid not knowing what you are doing and how to arrive at the right answer? Thanks.
 
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  • #2
[tex]1000g LiOH \frac{(12.01+32.0)g CO_2}{2(6.941+16.0+1.01)g LiOH} = 919g CO_2[/tex]

?
 
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  • #3
rocophysics said:
[tex]1000g LiOH \frac{(12.01+32.0)g CO_2}{2(6.941+16.0+1.01)g LiOH} = 14.8g CO_2[/tex]

?

My book says the answer is 920g.
 
  • #4
lLovePhysics said:
My book says the answer is 920g.
lol damn I'm way off, ok let me check

EDIT: ok i obviously shouldn't calculate in the dark, lol

i got 919g CO2

since you have a 2:1 stoichiometric ratio between LiOH and CO_2. i assume bc like to avoid writing too much, so i skip out on the moles and assume they cancel out nicely and just stick to the units that i am required in my answer.
 
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1. Can you explain the logic behind the method in question?

Before determining whether a method is wrong or not, it is important to understand the logic behind it. This will help in identifying any flaws or errors in the reasoning process.

2. What are the potential limitations or biases in the method?

Even if a method seems logical, it may have limitations or biases that can lead to incorrect conclusions. It is important to critically evaluate the method and consider any potential flaws.

3. Are there any alternative methods that could provide a different perspective?

Sometimes, what may seem logical to one person may not seem logical to another. This is why it is important to consider alternative methods that may provide a different perspective and help in determining the accuracy of the original method.

4. Have the results of the method been tested and replicated?

In science, it is important for methods to be tested and replicated in order to ensure the reliability of the results. If a method has not been tested or replicated, its accuracy may be questionable.

5. Are there any underlying assumptions in the method that may be incorrect?

Oftentimes, methods are based on certain assumptions. If these assumptions are incorrect, it can lead to faulty conclusions. It is important to carefully examine the underlying assumptions of a method to determine its validity.

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