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Ch.13 - Properties of Solutions
Brown - Chemistry: The Central Science 14th Edition
Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232Not the one you use?Change textbook
All textbooksBrown 14th EditionCh.13 - Properties of SolutionsProblem 51c
Chapter 13, Problem 51c

Calculate the number of moles of solute present in each of the following aqueous solutions: (c) 124.0 g of a solution that is 6.45% glucose (C6H12O6) by mass.

Verified step by step guidance
1
Identify the mass percentage of glucose in the solution, which is given as 6.45%.
Calculate the mass of glucose in the solution by multiplying the total mass of the solution (124.0 g) by the mass percentage (6.45%) expressed as a decimal.
Determine the molar mass of glucose (C_6H_12O_6) by adding the atomic masses of all the atoms in the molecular formula: 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms.
Use the mass of glucose obtained in step 2 and the molar mass from step 3 to calculate the number of moles of glucose using the formula: \( \text{moles} = \frac{\text{mass of glucose}}{\text{molar mass of glucose}} \).
The result from step 4 will give you the number of moles of glucose present in the solution.

Key Concepts

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

Percent by Mass

Percent by mass is a way to express the concentration of a solution, indicating the mass of solute present in a given mass of solution. In this case, a 6.45% glucose solution means that there are 6.45 grams of glucose for every 100 grams of solution. This concept is essential for determining the mass of solute in a specific mass of solution.

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). For glucose (C6H12O6), the molar mass is approximately 180.18 g/mol. Knowing the molar mass allows us to convert between grams of solute and moles, which is crucial for calculating the number of moles in a solution.
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Moles of Solute

The number of moles of solute can be calculated using the formula: moles = mass (g) / molar mass (g/mol). This relationship is fundamental in stoichiometry and solution chemistry, as it allows us to quantify the amount of solute present in a solution, which is necessary for various calculations in chemistry.
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