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Questions and Answers
What is the total energy content of a 228-g portion with 5g protein, 31g carbs, and 12g fat?
What is the total energy content of a 228-g portion with 5g protein, 31g carbs, and 12g fat?
What is the relationship between a Calorie and a calorie?
What is the relationship between a Calorie and a calorie?
In the context of nutrition, how many Calories per gram do fats and oils provide?
In the context of nutrition, how many Calories per gram do fats and oils provide?
What is the energy expenditure unit commonly used to measure human metabolism?
What is the energy expenditure unit commonly used to measure human metabolism?
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How are whole-room calorimeters different from whole-body calorimeters?
How are whole-room calorimeters different from whole-body calorimeters?
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What does bomb calorimetry involve in determining the caloric content of foods?
What does bomb calorimetry involve in determining the caloric content of foods?
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What is the energy unit used to quantify the amount of energy derived from metabolism of foods?
What is the energy unit used to quantify the amount of energy derived from metabolism of foods?
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How many whole-body calorimeters have been built since the first one in 1899?
How many whole-body calorimeters have been built since the first one in 1899?
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$0.963 g$ of benzene burned in a bomb calorimeter caused a temperature increase of $8.39°C$. How much heat was produced?
$0.963 g$ of benzene burned in a bomb calorimeter caused a temperature increase of $8.39°C$. How much heat was produced?
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What is the relationship between a Calorie and a calorie?
What is the relationship between a Calorie and a calorie?
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What is the total energy content of a 228-g portion with 5g protein, 31g carbs, and 12g fat?
What is the total energy content of a 228-g portion with 5g protein, 31g carbs, and 12g fat?
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In bomb calorimetry, how is the caloric content of foods determined?
In bomb calorimetry, how is the caloric content of foods determined?
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Which macronutrient provides about 9 Calories per gram in foods?
Which macronutrient provides about 9 Calories per gram in foods?
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How are whole-room calorimeters different from whole-body calorimeters?
How are whole-room calorimeters different from whole-body calorimeters?
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What unit is typically used to measure human metabolism in Calories per day?
What unit is typically used to measure human metabolism in Calories per day?
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How accurate are the caloric content values on food labels?
How accurate are the caloric content values on food labels?
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$0.963 g$ of benzene burned in a bomb calorimeter caused a temperature increase of $8.39°C$. How much heat was produced?
$0.963 g$ of benzene burned in a bomb calorimeter caused a temperature increase of $8.39°C$. How much heat was produced?
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How much heat was produced when 3.12 g of glucose was burned?
How much heat was produced when 3.12 g of glucose was burned?
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Which macronutrient provides about 4 Calories per gram in foods?
Which macronutrient provides about 4 Calories per gram in foods?
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What is the calorimeter bomb's heat capacity that is submerged in 925 mL of water?
What is the calorimeter bomb's heat capacity that is submerged in 925 mL of water?
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How much heat was produced when 0.963 g of benzene was burned?
How much heat was produced when 0.963 g of benzene was burned?
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What units are used to quantify the amount of energy in foods on nutritional labels?
What units are used to quantify the amount of energy in foods on nutritional labels?
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$0.963 g$ of benzene burned in a bomb calorimeter caused a temperature increase of $8.39°C$. How much heat was produced?
$0.963 g$ of benzene burned in a bomb calorimeter caused a temperature increase of $8.39°C$. How much heat was produced?
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What is the relationship between a Calorie (with a capital 'C') and a calorie?
What is the relationship between a Calorie (with a capital 'C') and a calorie?
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How much heat was produced when 0.963 g of benzene was burned?
How much heat was produced when 0.963 g of benzene was burned?
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What unit is typically used to measure human metabolism in Calories per day?
What unit is typically used to measure human metabolism in Calories per day?
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What is the energy unit used to quantify the amount of energy derived from metabolism of foods?
What is the energy unit used to quantify the amount of energy derived from metabolism of foods?
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How are whole-room calorimeters different from whole-body calorimeters?
How are whole-room calorimeters different from whole-body calorimeters?
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Study Notes
Calorimetry
- Calorimetry is a technique used to measure the amount of heat involved in a chemical or physical process.
- It is based on the principle of heat transfer between a system and its surroundings.
- A calorimeter is a device used to measure heat transfer, and it is designed to operate at constant pressure.
- There are different types of calorimeters, including:
- Coffee cup calorimeters: simple and inexpensive, but less accurate.
- Bomb calorimeters: more accurate and used for reactions that produce large amounts of heat and gaseous products.
Heat Transfer
- Heat transfer occurs between a system and its surroundings.
- The amount of heat transferred is proportional to the temperature change, specific heat, and mass of the substance.
- The heat gained by one substance is equal to the heat lost by another substance.
Heat of Reaction
- The heat of reaction is the amount of heat produced or consumed during a chemical reaction.
- It is calculated using the formula: qreaction = -qsolution.
- The heat of reaction can be measured using a calorimeter.
Calorimetry Problems
- Calorimetry problems typically involve calculating the heat of reaction, heat gained or lost, or temperature change.
- The problems require the use of specific heat, mass, and temperature change data.
Examples of Calorimetry
- Dissolving NH4NO3 in water: an endothermic process that absorbs heat.
- Burning glucose in a bomb calorimeter: an exothermic process that produces heat.
- Measuring the heat of reaction between HCl and NaOH: an exothermic process that produces heat.
- Using hand warmers: an exothermic process that produces heat through crystallization or oxidation reactions.
Thermochemistry
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Thermochemistry is the study of the relationships between heat, work, and energy.
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It is an important area of study in chemistry and has many practical applications.
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Calorimetry is a key technique used in thermochemistry to measure heat transfer and calculate energy changes.### Calorimetry
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Calorimetry is a technique used to measure the amount of heat involved in a chemical or physical process.
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It involves the use of a calorimeter, a device that measures the heat transferred to or from a substance.
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The temperature change measured by the calorimeter is used to derive the amount of heat transferred by the process under study.
Calorimeter
- A calorimeter is a device used to measure the amount of heat involved in a chemical or physical process.
- It is designed to minimize heat exchange with the surroundings.
- There are different types of calorimeters, including:
- Coffee cup calorimeters (simple and inexpensive)
- Commercial solution calorimeters (more accurate)
- Bomb calorimeters (used to measure the heat produced by a reaction that yields large amounts of heat and gaseous products)
Heat Transfer
- When a substance at a higher temperature is placed in contact with a substance at a lower temperature, heat will flow from the higher temperature substance to the lower temperature substance.
- The temperature of the higher temperature substance will decrease, while the temperature of the lower temperature substance will increase, until they reach thermal equilibrium.
- The heat gained by one substance is equal to the heat lost by the other substance: qsubstance M = -qsubstance W
Calculation of Heat Transfer
- The heat transfer can be calculated using the formula: q = c × m × ΔT
- Where q is the heat transfer, c is the specific heat, m is the mass of the substance, and ΔT is the temperature change.
Applications of Calorimetry
- Calorimetry is used to measure the energy content of foods.
- It is used in the study of chemical reactions and metabolism.
- It is used in the development of better rocket fuels.
- It is used to measure the specific heat of a substance.
Examples of Calorimetry
- Measuring the heat involved in the dissolution of a solid in water.
- Measuring the heat produced by a reaction in a bomb calorimeter.
- Measuring the heat transferred between two substances at different temperatures.
- Identifying a metal by measuring its specific heat.
Key Terms
- System: the substance or substances undergoing the chemical or physical change.
- Surroundings: all other matter, including components of the measurement apparatus, that serve to either provide heat to the system or absorb heat from the system.
- Specific heat: the amount of heat required to raise the temperature of a substance by 1°C.
- Nutritional calorie (Calorie): a unit of energy used to quantify the amount of energy derived from the metabolism of foods.### Calorimetry
- Calorimetry is a technique used to measure the amount of heat involved in a chemical or physical process.
- It is used to measure the heat transferred to or from a substance, and the measurement of heat transfer using this approach requires the definition of a system and its surroundings.
- A calorimeter is a device used to measure the amount of heat involved in a chemical or physical process.
Heat Transfer
- Heat transfer occurs between substances at different temperatures, and the temperature of the substances will change until they reach thermal equilibrium.
- The heat gained by one substance is equal to the heat lost by the other substance: qsubstance M = -qsubstance W
Calorimetry of Chemical Reactions
- Calorimetry is used to determine the heat involved in a chemical reaction, and the same principles of heat transfer apply.
- The amount of heat produced or consumed in the reaction (the "system"), qreaction, plus the heat absorbed or lost by the solution (the "surroundings"), qsolution, must add up to zero: qreaction + qsolution = 0
- This means that the amount of heat produced or consumed in the reaction equals the amount of heat absorbed or lost by the solution: qreaction = -qsolution
Applications of Calorimetry
- Calorimetry is used to measure the energy content of foods, and is an important tool in understanding the heat transferred in reactions involving everything from microscopic proteins to massive machines.
- It is used to measure the metabolism of individuals under different environmental conditions, and to develop better recommendations and regimens for nutrition, exercise, and general wellbeing.
Types of Calorimeters
- Bomb calorimeters are used to measure the energy produced by reactions that yield large amounts of heat and gaseous products, such as combustion reactions.
- Whole-body calorimeters are used to measure the metabolism of individuals, and are designed to hold an individual human being.
- Coffee cup calorimeters are simple and inexpensive, and are often used by students to measure the heat involved in chemical reactions.
Calculations
- The heat involved in a process can be calculated using the formula: q = c × m × ΔT
- The specific heat of a substance is a measure of the amount of heat energy required to raise the temperature of a unit mass of the substance by one degree Celsius.
- The specific heat of a substance is a unique property of that substance, and is used to calculate the heat involved in a process.
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Description
This quiz involves calculating the amount of heat produced in an exothermic reaction. Given the volumes and concentrations of the reactants, as well as the temperature change in the calorimeter, you need to determine the heat produced. The reaction involves the neutralization of HCl and NaOH to form NaCl and water.
