Textbook Question
The density of acetonitrile (CH3CN) is 0.786 g/mL and the density of methanol (CH3OH) is 0.791 g/mL. A solution is made by dissolving 22.5 mL of CH3OH in 98.7 mL of CH3CN. (b) What is the molality of the solution?
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Ch.13 - Properties of Solutions
Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232
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Table of contents
- Ch.1 - Introduction: Matter, Energy, and Measurement140
- Ch.2 - Atoms, Molecules, and Ions192
- Ch.3 - Chemical Reactions and Reaction Stoichiometry172
- Ch.4 - Reactions in Aqueous Solution156
- Ch.5 - Thermochemistry151
- Ch.6 - Electronic Structure of Atoms137
- Ch.7 - Periodic Properties of the Elements127
- Ch.8 - Basic Concepts of Chemical Bonding143
- Ch.9 - Molecular Geometry and Bonding Theories167
- Ch.10 - Gases147
- Ch.11 - Liquids and Intermolecular Forces97
- Ch.12 - Solids and Modern Materials129
- Ch.13 - Properties of Solutions126
- Ch.14 - Chemical Kinetics175
- Ch.15 - Chemical Equilibrium107
- Ch.16 - Acid-Base Equilibria127
- Ch.17 - Additional Aspects of Aqueous Equilibria133
- Ch.18 - Chemistry of the Environment88
- Ch.19 - Chemical Thermodynamics140
- Ch.20 - Electrochemistry137
- Ch.21 - Nuclear Chemistry99
- Ch.22 - Chemistry of the Nonmetals66
- Ch.23 - Transition Metals and Coordination Chemistry69
- Ch.24 - The Chemistry of Life: Organic and Biological Chemistry11
Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232Not the one you use?Change textbook
Chapter 13, Problem 48d
Ascorbic acid (vitamin C, C6H8O6) is a water-soluble vitamin. A solution containing 80.5 g of ascorbic acid dissolved in 210 g of water has a density of 1.22 g/mL at 55 °C. Calculate (d) the molarity of ascorbic acid in this solution.
Verified step by step guidance1
First, calculate the number of moles of ascorbic acid (C6H8O6) using its molar mass. The molar mass of C6H8O6 is calculated by adding the atomic masses of all the atoms in the formula: (6 * 12.01 g/mol for carbon) + (8 * 1.01 g/mol for hydrogen) + (6 * 16.00 g/mol for oxygen).
Next, use the formula for moles: \( \text{moles} = \frac{\text{mass}}{\text{molar mass}} \). Substitute the mass of ascorbic acid (80.5 g) and the molar mass calculated in the previous step to find the number of moles of ascorbic acid.
Calculate the total volume of the solution in liters. Use the density of the solution (1.22 g/mL) to find the volume: \( \text{volume} = \frac{\text{mass of solution}}{\text{density}} \). The mass of the solution is the sum of the mass of ascorbic acid and the mass of water (80.5 g + 210 g). Convert the volume from mL to L by dividing by 1000.
Finally, calculate the molarity of the ascorbic acid solution using the formula: \( \text{Molarity (M)} = \frac{\text{moles of solute}}{\text{liters of solution}} \). Substitute the number of moles of ascorbic acid and the volume of the solution in liters to find the molarity.
Review the calculations to ensure all units are consistent and the steps are followed correctly to determine the molarity of the ascorbic acid solution.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Molarity
Molarity is a measure of concentration defined as the number of moles of solute per liter of solution. It is expressed in moles per liter (mol/L). To calculate molarity, you need to know the amount of solute in moles and the total volume of the solution in liters. This concept is essential for understanding how concentrated a solution is and is commonly used in chemistry for preparing solutions.
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Molarity
Density
Density is defined as mass per unit volume and is typically expressed in grams per milliliter (g/mL) or kilograms per cubic meter (kg/m³). In this context, the density of the solution helps to convert the mass of the solution into volume, which is necessary for calculating molarity. Understanding density is crucial for determining how much space a given mass of solution occupies.
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Moles and Molar Mass
A mole is a unit in chemistry that represents 6.022 x 10²³ entities, such as atoms or molecules. The molar mass of a substance is the mass of one mole of that substance, typically expressed in grams per mole (g/mol). For ascorbic acid, knowing its molar mass allows you to convert grams of the substance into moles, which is a critical step in calculating molarity.
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Related Practice
Textbook Question
The density of acetonitrile (CH3CN) is 0.786 g/mL and the density of methanol (CH3OH) is 0.791 g/mL. A solution is made by dissolving 22.5 mL of CH3OH in 98.7 mL of CH3CN. (c) Assuming that the volumes are additive, what is the molarity of CH3OH in the solution?
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Textbook Question
The density of toluene (C7H8) is 0.867 g/mL, and the density of thiophene (C4H4S) is 1.065 g/mL. A solution is made by dissolving 8.10 g of thiophene in 250.0 mL of toluene. (a) Calculate the mole fraction of thiophene in the solution.
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Textbook Question
Ascorbic acid (vitamin C, C6H8O6) is a water-soluble vitamin. A solution containing 80.5 g of ascorbic acid dissolved in 210 g of water has a density of 1.22 g/mL at 55 °C. Calculate (c) the molality,
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Textbook Question
Ascorbic acid (vitamin C, C6H8O6) is a water-soluble vitamin. A solution containing 80.5 g of ascorbic acid dissolved in 210 g of water has a density of 1.22 g/mL at 55 °C. Calculate (a) the mass percentage,
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