Chemistry Calculating Molality and Mole Fraction for a 10% (by wt) Solution of KNO3

AI Thread Summary
To calculate the molality and mole fraction of a 10% (by weight) KNO3 solution, 1 g of KNO3 is dissolved in 9 g of water. The molar mass of KNO3 is 101.1 g/mol, resulting in approximately 0.00989 moles of KNO3. The total moles of the solution include 0.00989 moles of KNO3 and 0.5 moles of water, leading to a mole fraction of 0.0194 for KNO3. The molality is calculated as 0.00989 moles of KNO3 per 0.009 kg of water, yielding a value of 1.1 M. The calculations appear to be accurate.
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Homework Statement


A 10% (by wt) solution of KNO3 would have what molality and what mole fraction


Homework Equations


mole fraction = moles of KNO3/total moles
wt % = # g of solute/total g
molality = # moles KNO3/kg H2O


The Attempt at a Solution


1 g KNO3/10 g total
1 g KNO3/101.1 g/mol = .00989
9 g H2O/18 g/mol = .5 H20

.00989 mol KNO3 / (.00989+.5) = .0194 mole fraction
.00989 moles of KNO3 / .009 kg H20 = 1.1 M
 
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