Hi guys, I have this problem:
An organic compound, which contains C, H, O and Cl gave the following results: 0.16g produce from combustion 0.265g of CO2 and 0.0325g of H2O. If I melt 0.215g of the compound in water with the addiction of AgNO3 I obtain 0.236g of AgCl. Find the molecular formula of the compound. Molar mass is 130.5g/mol.
I obtained the mass of oxygen with the following operation:
(0.0325 + 0.265) - 0.16g from the reaction of combustion
I calculate moles of oxygen, hydrogen, carbon from CO2 and Cl from the salt, but the molecular formula that I found doesn’t march with the text result.
Can you help me ?
Thank you in advance.
Stoichiometry problem
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- ChenBeier
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Re: Stoichiometry problem
The calculation for oxygen is wrong, because the molecule also contain oxygen.
The masses of CO2 and H2O correspond to C and H. Calculate the moles of it and do a ratio to unbroken numbers.
The mass of silverchloride correspond to the mass of Chlorine. Do also mole ratio.
If you have C, H and Cl subtract it from the molar mass of the compound you get molar mass of oxygen.
The masses of CO2 and H2O correspond to C and H. Calculate the moles of it and do a ratio to unbroken numbers.
The mass of silverchloride correspond to the mass of Chlorine. Do also mole ratio.
If you have C, H and Cl subtract it from the molar mass of the compound you get molar mass of oxygen.
Re: Stoichiometry problem
Right, thank you very muchChenBeier wrote: ↑Sun Jan 28, 2024 6:12 am The calculation for oxygen is wrong, because the molecule also contain oxygen.
The masses of CO2 and H2O correspond to C and H. Calculate the moles of it and do a ratio to unbroken numbers.
The mass of silverchloride correspond to the mass of Chlorine. Do also mole ratio.
If you have C, H and Cl subtract it from the molar mass of the compound you get molar mass of oxygen.
- ChenBeier
- Distinguished Member
- Posts: 1569
- Joined: Wed Sep 27, 2017 7:25 am
- Location: Berlin, Germany
Re: Stoichiometry problem
What is your result?
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- Newbie
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Re: Stoichiometry problem
Can you give me the results to see if the answer is the same as mine?sottozer0 wrote: ↑Sun Jan 28, 2024 8:24 amRight, thank you very muchChenBeier wrote: ↑Sun Jan 28, 2024 6:12 am The calculation for oxygen is wrong, because the molecule also contain oxygen.
The masses of CO2 and H2O correspond to C and H. Calculate the moles of it and do a ratio to unbroken numbers.
The mass of silverchloride correspond to the mass of Chlorine. Do also mole ratio.
If you have C, H and Cl subtract it from the molar mass of the compound you get molar mass of oxygen.
- ChenBeier
- Distinguished Member
- Posts: 1569
- Joined: Wed Sep 27, 2017 7:25 am
- Location: Berlin, Germany
Re: Stoichiometry problem
Why not give yours first?