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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Problem of the Week Archive => Topic started by: Borek on May 27, 2013, 06:39:20 AM

What is the density of the sulfuric acid solution (g/mL) if its percent w/w concentration is 60.16% and w/v percent concentration is 90.24%?

bar cbvag svir g/mL?

[tex]
\LARGE{\sqrt[3]{3.375}}
[/tex]
g/ml

Have you used density tables?

I didn't.
ω(mass share)=m_{H2SO4}/m_{solution}=0.6016
φ(volume share)=V_{H2SO4}/V_{solution}=0.9024
Dividing:
ω/φ=V_{solution}/m_{solution}=0.6667
V_{solution}=0.6667m_{solution}
ρ_{solution}=m_{solution}/V_{solution}=m_{solution}/0.6667m_{solution}=1.5gcm^{3}

Have you used density tables?
Nope.

Have you used density tables?
:O No!
It's a fairly simple question. If 100 g of the soln contains 60.16 g of H_{2}SO_{4} and 100 mL of the solution contains 90.24 g of H_{2}SO_{4}, all one needs to find out is how many mL of soln corresponds to 60.16 g H_{2}SO_{4}, because this volume of soln which corresponds to 60.16 g of H_{2}SO_{4}, also weighs 100 g (given).

I know you don't have to. I was wondering how to word the question  whether to name the compound or not. If it is named, it suggests it is a specific case, not a general thing.

What's the justification for V[H2SO4]/m[H2SO4]=1?
Only then ρ[Solution]=Volume Share/Mass Share=1.500 g/cm^{3}. Otherwise Volume Share/Mass Share=ρ[Solution]*V[H2SO4]/m[H2SO4].

What's the justification for V[H2SO4]/m[H2SO4]=1?
Only then ρ[Solution]=Volume Share/Mass Share=1.500 g/cm^{3}. Otherwise Volume Share/Mass Share=ρ[Solution]*V[H2SO4]/m[H2SO4].
density of solution is always equal to mass / volume.
The rest of what you wrote didn't make any sense to me. Especially not what "share" applies to.
Your equations don't even make dimensional sense.

The rest of what you wrote didn't make any sense to me. Especially not what "share" applies to.
I was looking at Raderford's derivation as it is the only one on the page.
ω(mass share)=m_{H2SO4}/m_{solution}=0.6016
φ(volume share)=V_{H2SO4}/V_{solution}=0.9024
So there are the definitions of Mass Share and Volume Share.
Dividing:
ω/φ=V_{solution}/m_{solution}=0.6667
Look at the expressions for ω and φ; clearly ω/φ=m_{H2SO4}·V_{solution}/(m_{solution}·V_{H2SO4}). Only if m_{H2SO4}/V_{H2SO4}=1 does this reduce to ω/φ=V_{solution}/m_{solution}. What's the justification for that?

He has a Typo. V should be m.

He has a Typo. V should be m.
Ah I see. w/v. It's not volume fraction we want but mass concentration, so p[H2SO4]=m[H2SO4]/V[solution]. Got it now, thanks for the help.