What is the empirical formula of this compound help?

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Discussion Overview

The discussion revolves around determining the empirical formula of a hydrated compound based on its percentage composition of sodium (Na), sulfur (S), oxygen (O), and water (H2O). Participants explore various methods and calculations related to empirical formula derivation.

Discussion Character

  • Homework-related, Mathematical reasoning, Exploratory

Main Points Raised

  • One participant presents a percentage composition and proposes an empirical formula of Na2S2O3 - 5H2O, expressing confusion about the molar ratios of Na and S.
  • Another participant suggests that showing the work might lead to more responses and clarity in the calculations.
  • A different participant raises a question about the molar ratios, noting that their calculation led to Na5S5O4*22H2O, indicating a potential discrepancy in the number of oxygen atoms compared to Na and S.
  • One participant mentions assuming a mass of 100 grams for the calculations and converting to moles.
  • Two participants share a poem that outlines a method for converting percentage composition to an empirical formula, indicating its usefulness in the calculations.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the empirical formula, and multiple competing views and calculations are presented without resolution.

Contextual Notes

Some calculations may depend on assumptions made about the mass of the sample, and there are unresolved questions regarding the molar ratios of the elements involved.

Larrytsai
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A hydrated substance was found to have the following percentage composition= Na 18.53%
S= 25.87%
O= 10.34%
H2O= 62.9%
What is the empirical formula of this compound?


what i got was Na2S2O3 - 5H2O
but I am confused cause Na and S are both 0.806 mols
 
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Perhaps, if you showed your work you might get more answers.
 
10.34/16 < 18.53/23 and 25.87/32, but you have more O atoms in your formula than Na and S. How is that? I got Na5S5O4*22H2O, but that's probably not right.
 
umm hmm i assumed 100 grams and then converted to mols
 
Use this cool poem.

Percent to mass
Mass to mole
Divide by small
Multiply 'til whole
Poem by "Joel S. Thompson"
 
MichaelXY said:
Use this cool poem.

Percent to mass
Mass to mole
Divide by small
Multiply 'til whole
Poem by "Joel S. Thompson"

That's pretty neat! I'll have to remember that.
 

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