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Ch.5 - Thermochemistry
Brown - Chemistry: The Central Science 14th Edition
Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232당신이 사용하는 게 아니라요?교과서 변경
모든 교과서Brown 14th EditionCh.5 - Thermochemistry문제 46a
5장, 문제 46a

At one time, a common means of forming small quantities of oxygen gas in the laboratory was to heat KClO3: 2 KClO3(s) → 2 KCl(s) + 3 O2(g) ΔH = -89.4 kJ For this reaction, calculate H for the formation of (a) 1.36 mol of O2

검증된 단계별 안내
1
Identify the given reaction: 2 KClO_3(s) → 2 KCl(s) + 3 O_2(g) with ΔH = -89.4 kJ.
Understand that ΔH = -89.4 kJ is for the formation of 3 moles of O_2.
Set up a proportion to find ΔH for 1.36 moles of O_2: (ΔH for 1.36 mol O_2) / (ΔH for 3 mol O_2) = 1.36 mol / 3 mol.
Solve the proportion to find ΔH for 1.36 moles of O_2.
Ensure the units are consistent and the sign of ΔH reflects the exothermic nature of the reaction.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
3m

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Stoichiometry

Stoichiometry is the branch of chemistry that deals with the quantitative relationships between the reactants and products in a chemical reaction. It allows us to calculate the amounts of substances consumed and produced in a reaction based on balanced chemical equations. In this case, the stoichiometric coefficients from the reaction indicate that 3 moles of O2 are produced for every 2 moles of KClO3 decomposed.
추천 영상:
가이드 코스
01:16
Stoichiometry Concept

Enthalpy Change (ΔH)

Enthalpy change (ΔH) is a measure of the heat content of a system at constant pressure. It indicates whether a reaction is exothermic (releases heat, ΔH < 0) or endothermic (absorbs heat, ΔH > 0). In the given reaction, ΔH = -89.4 kJ signifies that the decomposition of KClO3 releases 89.4 kJ of energy for every 2 moles of KClO3 reacted, which is crucial for calculating the energy change for the formation of 1.36 moles of O2.
추천 영상:
가이드 코스
02:34
Enthalpy of Formation

Molar Relationships

Molar relationships refer to the ratios of moles of reactants and products in a balanced chemical equation. These relationships are essential for converting between moles of different substances. In this scenario, knowing that 3 moles of O2 are produced from 2 moles of KClO3 allows us to determine the amount of energy associated with the formation of 1.36 moles of O2 by using the established stoichiometric ratios.
추천 영상:
가이드 코스
01:13
Molarity
관련 실천
교과서 질문

At one time, a common means of forming small quantities of oxygen gas in the laboratory was to heat KClO3: 2 KClO3(s) → 2 KCl(s) + 3 O2(g) ΔH = -89.4 kJ (c) The decomposition of KClO3 proceeds spontaneously when it is heated. Do you think that the reverse reaction, the formation of KClO3 from KCl and O2, is likely to be feasible under ordinary conditions? Explain your answer.

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교과서 질문

When solutions containing silver ions and chloride ions are mixed, silver chloride precipitates Ag+(aq) + Cl-(aq) → AgCl(s) H = -65.5 kJ (a) Calculate H for the production of 0.450 mol of AgCl by this reaction. (b) Calculate H for the production of 9.00 g of AgCl. (c) Calculate H when 9.25⨉10-4 mol of AgCl dissolves in water.

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교과서 질문

At one time, a common means of forming small quantities of oxygen gas in the laboratory was to heat KClO3: 2 KClO3(s) → 2 KCl(s) + 3 O2(g) ΔH = -89.4 kJ For this reaction, calculate H for the formation of (b) 10.4 g of KCl.

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교과서 질문

Consider the following reaction: 2 CH3OH(g) → 2 CH4(g) + O2(g) ΔH = +252.8 kJ (d) How many kilojoules of heat are released when 38.5 g of CH4(g) reacts completely with O2(g) to form CH3OH(g) at constant pressure?

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교과서 질문

Consider the following reaction: 2 CH3OH(g) → 2 CH4(g) + O2(g) ΔH = +252.8 kJ (c) For a given sample of CH3OH, the enthalpy change during the reaction is 82.1 kJ. How many grams of methane gas are produced?

교과서 질문

Consider the combustion of liquid methanol, CH3OH(l): CH3OH(l) + 3/2 O2(g) → CO2(g) + 2 H2O(l) ΔH = -726.5 kJ (a) What is the enthalpy change for the reverse reaction?

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