Gas Stoichiometry: Find Molecular Formula of CHCl

  • Thread starter Thread starter magma_saber
  • Start date Start date
  • Tags Tags
    Gas
Click For Summary

Discussion Overview

The discussion revolves around determining the molecular formula of a compound with the empirical formula CHCl, using gas stoichiometry and the ideal gas law. Participants are attempting to apply the equation PV=nRT to solve the problem, focusing on the relationship between moles and mass of the gas.

Discussion Character

  • Homework-related
  • Mathematical reasoning
  • Technical explanation

Main Points Raised

  • One participant states the need to use the ideal gas law (PV=nRT) to find the number of moles (n) of the compound.
  • Another participant suggests combining the calculated number of moles with the given mass of the compound to progress towards finding the molecular formula.
  • There is confusion expressed about how the number of moles relates to the molecular formula, with participants questioning the utility of finding n alone.
  • Participants discuss the importance of understanding the relationship between moles and grams in chemical calculations, emphasizing that they cannot simply add these two quantities.

Areas of Agreement / Disagreement

Participants do not reach a consensus on how to proceed with the problem. There is ongoing confusion about the relationship between the number of moles and the molecular formula, indicating that multiple viewpoints and uncertainties remain in the discussion.

Contextual Notes

Participants have not fully clarified the steps needed to derive the molecular formula from the empirical formula and the calculated number of moles. There are unresolved questions about the calculations and the necessary conversions between mass and moles.

Who May Find This Useful

This discussion may be useful for students learning about gas laws, stoichiometry, and the relationships between empirical and molecular formulas in chemistry.

magma_saber
Messages
73
Reaction score
0

Homework Statement


A compound has the empirical formula CHCl. A 256 mL flask, at 373 K and 750. torr, contains 0.800 g of the gaseous compound. Give the molecular formula.


Homework Equations


Only equation i know that relates to this is PV=nRT.


The Attempt at a Solution


I have absolutely no idea.
 
Physics news on Phys.org
That's the right equation. Plug in all the numbers you can into it, and see what happens.
 
All that will give me is "n." what good does that do?
 
n and 0.8 g - combine these two numbers.
 
how does that give me the molecular formula? I'm still lost...
 
The empirical formula is CHCl. Given that, what are the possible molecular formulas?
 
magma_saber said:
how does that give me the molecular formula? I'm still lost...

Check what it does give you. Very important property of substance.
 
Borek said:
n and 0.8 g - combine these two numbers.

By this do you mean add n and 0.8? If so then i get 0.808. now what?
 
No, I didn't told you have to add them. Look at the units - one is number of moles, second is grams. You can't add them just like that.

There is a very important property of each reagent that combines moles and grams, and is extensively used in all almost chemical calculations. Seems to me like you have calculated that 0.008 mole is 0.8 g. Can you calculate now mass of other number of moles of the same substance?
 

Similar threads

Chemistry Finding the molecular formula of an unknown hydrocarbon
  • · Replies 4 ·
Replies
4
Views
3K
Chemistry Finding the Chemical Formula and Relative Molecular Mass
  • · Replies 13 ·
Replies
13
Views
4K
Chemistry How can I find the molecular formula in this problem?
  • · Replies 10 ·
Replies
10
Views
3K
Final Pressure of Gas Mixture After Reaction Completed
  • · Replies 10 ·
Replies
10
Views
5K
Chemistry Combustion Analysis- Empirical and molecular formula
  • · Replies 8 ·
Replies
8
Views
4K
Ideal Gas Law solve for partial pressure
  • · Replies 2 ·
Replies
2
Views
4K
How to Calculate the Pressure of Each Element in a Compound Mixture?
  • · Replies 5 ·
Replies
5
Views
2K
Finding volume of one compound using Stoichiometry equation
  • · Replies 2 ·
Replies
2
Views
2K
Chemistry Molecular formula of organic compound
  • · Replies 2 ·
Replies
2
Views
2K
How Do You Calculate the Molecular Formula of a Gas Compound in Stoichiometry?
  • · Replies 7 ·
Replies
7
Views
3K