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Ch.6 - Thermochemistry
Chapter 6, Problem 35

Suppose that a person eats 2387 Calories per day. Convert this amount of energy into each unit. a. J b. kJ c. kWh

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1
Understand that 1 Calorie (with a capital 'C', also known as a kilocalorie) is equivalent to 1000 calories (with a lowercase 'c', also known as small calories).
Recognize that 1 calorie is defined as the amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius, and it is equivalent to 4.184 joules.
Convert the daily energy intake from Calories to joules using the conversion factor: 1 Calorie = 4184 joules.
Convert the total joules to kilowatt-hours (kWh), knowing that 1 kWh = 3.6 x 10^6 joules.
Calculate the total energy in kWh by dividing the total joules by the number of joules in one kWh.

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Key Concepts

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

Calorie to Joule Conversion

A Calorie (specifically, a kilocalorie) is a unit of energy defined as the amount of energy needed to raise the temperature of one kilogram of water by one degree Celsius. In scientific contexts, energy is often expressed in Joules, where 1 Calorie is equivalent to approximately 4.184 Joules. Understanding this conversion is essential for translating dietary energy into other energy units.
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Joule to Kilowatt-Hour Conversion

A kilowatt-hour (kWh) is a unit of energy equivalent to one kilowatt (1,000 watts) of power used for one hour. To convert Joules to kilowatt-hours, the conversion factor is used: 1 kWh equals 3.6 million Joules (3.6 x 10^6 J). This conversion is crucial for expressing energy consumption in terms familiar to electrical energy usage.
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Energy Units in Context

Different contexts require different units of energy. In nutrition, energy is often measured in Calories, while in physics and engineering, Joules and kilowatt-hours are more common. Understanding the context of energy measurement helps in making appropriate conversions and comprehending the implications of energy consumption in daily life.
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