객관식
Consider the following reaction:
2 C6H6 (l) + 15 O2 (g) → 12 CO2 (g) + 6 H2O (g) ∆Hº = – 6278 kJ
What volume of benzene (C6H6, d = 0.880 g/mL, molar mass = 78.11 g/mol) is necessary to evolve 5.19 x 109 kJ of heat?
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8. Quantities in Chemical Reactions
Thermochemical Equations
2:21분문제 26
교과서 질문
Converting liquid water to solid ice releases 1.44 kcal/mol (6.02 kJ/mol). How many kilocalories are released by freezing 32 g of H2O?
검증된 단계별 안내1
Determine the molar mass of water (H2O) by adding the atomic masses of hydrogen and oxygen: 2(1.01 g/mol) + 16.00 g/mol.
Calculate the number of moles of water in 32 g by dividing the mass of water by its molar mass.
Use the given energy release per mole (1.44 kcal/mol) to find the total energy released by multiplying the number of moles by the energy per mole.
Ensure the units are consistent and convert if necessary, but since the problem asks for kilocalories, no conversion is needed.
Summarize the calculation to find the total kilocalories released when 32 g of water freezes.
비슷한 문제에 대한 검증된 영상 답변:이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
2m주요 개념
질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.
Molar Mass of Water
The molar mass of water (H2O) is approximately 18 g/mol. This value is essential for converting grams of water to moles, which is necessary for calculating energy changes in chemical reactions, such as phase changes. In this case, knowing the molar mass allows us to determine how many moles of water are present in 32 g.
추천 영상:
가이드 코스
01:10
Calculating Molar Mass
Phase Change and Latent Heat
Phase changes, such as freezing, involve the absorption or release of energy without a change in temperature. The latent heat of fusion for water is the amount of energy released when water freezes, quantified here as 1.44 kcal/mol. Understanding this concept is crucial for calculating the total energy released when a specific mass of water freezes.
추천 영상:
가이드 코스
09:03The Heating Curve
Energy Calculation in Chemistry
In chemistry, energy calculations often involve converting between moles and grams, as well as applying specific energy values associated with phase changes. To find the total energy released when freezing 32 g of water, one must first convert grams to moles and then multiply by the energy released per mole, ensuring accurate results in thermodynamic calculations.
추천 영상:
가이드 코스
01:26Nature of Energy
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