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Caio06
Jr. Member
Joined: 16 Sep 2018
Posts: 5


HELP!!! I need help with this question


A bottle with a volume of 0.85 L is filled up with CO2 at a pressure of 1.44 atm and temperature of 312 K. Upon adding LiOH into this bottle, it is found that the pressure of CO2 reduces to 0.56 atm because some of CO2 reacts with LiOH. Calculate the amount of Li2CO3 that is generated (Li = 7, C = 12,O = 16, H = 1)
CO2(g) + 2LiOH(aq) = Li2CO3(aq) + H2O(l) [/b] 

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Caio06
Jr. Member
Joined: 16 Sep 2018
Posts: 5




my results do not correspond to the result given by the teacher 

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ChenBeier
Sr. Staff Member
Joined: 27 Sep 2017
Posts: 208
Location: Berlin, Germany




Show your calculation first.
Do you know ideal gas law?
What are the constant values in this case. What is relation of mole and pressure. 

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Caio06
Jr. Member
Joined: 16 Sep 2018
Posts: 5




First i calculated the numbers of moles of CO2 using the first pressure given(1,44atm).
n=PV/RT
n=(1,44)x(0,85)/(0,08206)x(312)
n=0,048 mol of CO2
After i did the same using the last pressure given (0,56 atm) using the same volume ,temperature, which give me 0,0189 moles, so i did the difference between the first and the last what give me 0,029 moles, what i supose is the moles of Li2CO3.
Lastly i did the stoichiometry to find the mass.
0,029mol Li2C03 x (73,9g Li2CO3/1 mol Li2C03)
=2,14 g of Li2CO3
The result given by the teacher is 1,628g. 

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ChenBeier
Sr. Staff Member
Joined: 27 Sep 2017
Posts: 208
Location: Berlin, Germany




Your calculation is correct. I got the same result. Maybe you can get the calculation from your teacher. 

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Caio06
Jr. Member
Joined: 16 Sep 2018
Posts: 5


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ChenBeier
Sr. Staff Member
Joined: 27 Sep 2017
Posts: 208
Location: Berlin, Germany




Do you have the teachers calculation? 

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Caio06
Jr. Member
Joined: 16 Sep 2018
Posts: 5




Not yet, when I have it, I'll post it here. 

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