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Ch.13 - Properties of Solutions

Chapter 13, Problem 58b

Caffeine (C8H10N4O2) is a stimulant found in coffee and tea. If a solution of caffeine in the solvent chloroform (CHCl3) has a concentration of 0.0500 m, calculate (b) the mole fraction of caffeine in the solution.

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Hello everyone. Today we are being given the falling problem. Theo bromine is an alkaloid found in cocoa plants. This compound President chocolate and is the reason why it is poisonous to dogs. Theo bromine is dissolved in methanol to a final concentration of 1. morality. What is the mole fraction of theO bombing in the solution? So morality represented by lower case M is the moles of our salute divided by kilograms of solvent. So for the moses saw you, you have 1.5 moles of our theo brimming Divided by the kg of Solvent, which is one kg of our methanol. To give us a morality of 1.5. So from there we can calculate our moles of methanol. So we're gonna start off with the one kg of methanol you're given. And we're gonna convert that first. We're gonna convert kilograms two g. By using conversion factor that one kg is equal to 10 to the third grams. We're gonna multiply by the fact that one mole of methanol Is equal to a smaller mass, which according to the periodic table is 32.04 g. This is gonna give us 31.2 moles of methanol. So now we have the moles of methanol. And from there we can finally calculate our mole fraction. So our mole fraction is going to be equal to the moles of our salute divided by the moles of our solution. So our silly, which is theo bro mean The number of moles is 1.5 moles And then the most of the solution is going to be that 1.5 moles plus the moles of methanol, which we calculated to be 31.2. If we were to put this into our calculator, we would get a final mole fraction of zero 459 as our final answer. And with that we have solved the problem Overall, I hope this helped hand until next time.