Calculate the molar ratio of copper to sulfur in the compound, expressed as a decimal number. (e.g.: 3.05, not 3.05:1) Show your calculation and round appropriately the ratio you get.
So, I've figured out my percentages and moles.
There is 83.74% Cu
And 21.97% S
In moles, if my calculations are correct, we would have:
0.309 g Cu * 1 mol Cu/63.546 g Cu = 0.005 moles
0.087 g S * 1 mol S/32.06 g S = 0.003 moles.
So to calculate the ratio, what would I do? I feel as if my mole calculation may be wrong, or there is an error. Can I get a ratio with such small numbers?
Thanks, I really do appreciate the help. Your time means a lot.
There is also another question that asks "The actual ratio must be the ratio of two integers. Determine the most likely actual ratio of copper to sulfur, based on your answer above, and use it to write the empirical formula of your compound in the box".
What is the difference between the question asking the ratio of copper to sulfur and the question asking the ratio of two integers. sorry if this is a dumb question, i just want the clarification.
.005/.003 = 5/3
Cu5S3
5 molecules of Copper for every 3 of Sulfur
(a mol is just Avagadro's number of molecules, like saying a dozen)
0.309 g Cu * 1 mol Cu/63.546 g Cu = 0.005 moles
0.087 g S * 1 mol S/32.06 g S = 0.003 moles.
Why did you round off so much; i.e., 0.309/63.54 = 0.00486 and
0.087/32.06 = 0.0027
So the ratio is 0.00486/0.0027 = 1.8 Cu to 1 S. I would think the most likely formula to be Cu2S. The difference between 1.8 and 2 is experimental error.
To calculate the molar ratio of copper to sulfur, you need to determine the ratio of the number of moles of copper to the number of moles of sulfur.
From your calculations, you obtained 0.005 moles of copper (Cu) and 0.003 moles of sulfur (S).
To find the molar ratio, divide the number of moles of copper by the number of moles of sulfur:
Ratio = Moles of Cu / Moles of S
Ratio = 0.005 moles Cu / 0.003 moles S
Simplifying this ratio gives:
Ratio = 1.67
Thus, the molar ratio of copper to sulfur in the compound is approximately 1.67.