Caffeine (C 8 H 10 N 4 O 2 ) is a stimulant found in coffee and tea. If a solution of caffeine in the solvent chloroform (CHCl 3 ) has a concentration of 0.0500 m, calculate (b) the mole fraction of caffeine in the solution.

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.

Ch.13 - Properties of Solutions

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Brown 14th Edition

Ch.13 - Properties of Solutions

Problem 58b

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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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Identify the given data: the molality (m) of the solution is 0.0500 m, which means there are 0.0500 moles of caffeine per kilogram of chloroform.

Calculate the molar mass of caffeine (C_8H_10N_4O_2) by adding the atomic masses of all the atoms: 8 carbon atoms, 10 hydrogen atoms, 4 nitrogen atoms, and 2 oxygen atoms.

Determine the mass of 1 kg of chloroform (CHCl_3) in moles by using its molar mass.

Calculate the total moles of the solution by adding the moles of caffeine to the moles of chloroform.

Find the mole fraction of caffeine by dividing the moles of caffeine by the total moles of the solution.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Mole Fraction

Mole fraction is a way of expressing the concentration of a component in a mixture. It is defined as the ratio of the number of moles of a specific component to the total number of moles of all components in the solution. For a solution, the mole fraction of a solute can be calculated using the formula: mole fraction = moles of solute / (moles of solute + moles of solvent).

Concentration

Concentration refers to the amount of a substance (solute) present in a given volume of solution or in a specific mass of solvent. In this case, the concentration of caffeine is given in molality (m), which is defined as the number of moles of solute per kilogram of solvent. Understanding how to convert between different concentration units is essential for solving problems involving solutions.

Chloroform as a Solvent

Chloroform (CHCl3) is a common organic solvent used in various chemical applications, including the dissolution of organic compounds. It is important to recognize the properties of chloroform, such as its density and molar mass, as these factors influence the calculation of moles of solvent when determining the mole fraction of a solute in a solution.