Textbook Question
(a) A serving of a particular ready-to-serve brown & wild rice meal contains 4.5 g fat, 42 g carbohydrate, and 4.0 g protein. Estimate the number of calories in a serving.
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Ch.5 - Thermochemistry
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 5, Problem 93
The heat of combustion of fructose, C6H12O6, is -2812 kJ/mol. If a fresh golden delicious apple weighing 120 g contains 16.0 g of fructose, what caloric content does the fructose contribute to the apple?
Verified step by step guidance1
Determine the molar mass of fructose (C_6H_{12}O_6) by adding the atomic masses of its constituent elements: C, H, and O.
Calculate the number of moles of fructose in 16.0 g using the formula: \( \text{moles} = \frac{\text{mass}}{\text{molar mass}} \).
Use the heat of combustion value (-2812 kJ/mol) to find the total energy released by the combustion of the calculated moles of fructose.
Convert the energy from kilojoules to calories using the conversion factor: 1 kJ = 239.006 calories.
The result from the previous step gives the caloric content contributed by the fructose in the apple.
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Heat of Combustion
The heat of combustion is the amount of energy released when a substance is completely burned in oxygen. It is typically expressed in kilojoules per mole (kJ/mol). For fructose, the heat of combustion is -2812 kJ/mol, indicating that this amount of energy is released when one mole of fructose is combusted.
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02:24
Combustion Apparatus
Molar Mass
Molar mass is the mass of one mole of a substance, usually expressed in grams per mole (g/mol). For fructose (C6H12O6), the molar mass is approximately 180.18 g/mol. This value is essential for converting between grams of fructose and moles, which is necessary for calculating the energy contribution from the fructose in the apple.
Recommended video:
Guided course
02:11Molar Mass Concept
Caloric Content Calculation
Caloric content calculation involves determining the energy provided by a specific mass of a substance based on its heat of combustion. To find the caloric content contributed by fructose in the apple, one must first convert the mass of fructose to moles and then multiply by the heat of combustion to find the total energy released, which can be expressed in kilojoules or converted to calories.
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02:28Stoichiometric Rate Calculations
Related Practice
Textbook Question
The heat of combustion of ethanol, C2H5OH(l), is -1367 kJ/mol. A bottle of stout (dark beer) contains up to 6.0% ethanol by mass. Assuming the density of the beer to be 1.0 g/mL, what is the caloric content due to the alcohol (ethanol) in a bottle of beer (500 mL)?
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Textbook Question
The standard enthalpies of formation of gaseous propyne (C3H4), propylene (C3H6), and propane (C3H8) are +185.4, +20.4, and -103.8 kJ/mol, respectively. (c) Which is the most efficient fuel in terms of heat evolved per unit mass?
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Textbook Question
It is interesting to compare the 'fuel value' of a hydrocarbon in a hypothetical world where oxygen is not the combustion agent. The enthalpy of formation of CF4(g) is -679.9 kJ/mol. Which of the following two reactions is the more exothermic?
CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g)
CH4(g) + 4 F2(g) → CF4(g) + 4 HF(g)
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