Thread: equation
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Old July 7th, 2005, 03:50
Borek Borek is offline
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Charco - you are reaching your left ear with your right hand. No idea why.

c%w/w = m_solute/m_solution * 100%

we know c%w/w, we know the mass of solute, we need mass of solution:

m_solution = m_solute/c%ww * 100%

m_solution = 25.00/35.00 * 100 = 71.43 g

density definition

d = m_solution / V_solution

so

V_solution = m_solution /d

V_solution = 71.43/1.3678 = 52.22 mL

Result the same, calculations three times shorter.

And density changes have nothing to do with the question - you can deal with the masses and the given density only.

c%w/w stands for mass percentage
m_solution, m_solute - masses
d - density
V-solution - volume

Best,
Borek