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Ch.10 - Gases
Brown - Chemistry: The Central Science 15th Edition
Brown15th EditionChemistry: The Central ScienceISBN: 9780137542970당신이 사용하는 게 아니라요?교과서 변경
10장, 문제 58

Both Jacques Charles and Joseph Louis Guy-Lussac were avid balloonists. In his original flight in 1783, Jacques Charles used a balloon that contained approximately 31,150 L of H2. He generated the H2 using the reaction between iron and hydrochloric acid: Fe1s2 + 2 HCl1aq2 ¡ FeCl21aq2 + H21g2 How many kilograms of iron were needed to produce this volume of H2 if the temperature was 22 °C?

검증된 단계별 안내
1
Identify the balanced chemical equation: \( \text{Fe (s)} + 2 \text{HCl (aq)} \rightarrow \text{FeCl}_2 \text{(aq)} + \text{H}_2 \text{(g)} \).
Use the ideal gas law to find the number of moles of \( \text{H}_2 \): \( PV = nRT \), where \( P \) is pressure, \( V \) is volume, \( n \) is moles, \( R \) is the gas constant, and \( T \) is temperature in Kelvin.
Convert the temperature from Celsius to Kelvin: \( T(K) = 22 + 273.15 \).
Assume standard pressure (1 atm) unless otherwise specified, and use \( R = 0.0821 \text{ L atm mol}^{-1} \text{ K}^{-1} \). Solve for \( n \), the moles of \( \text{H}_2 \).
Use stoichiometry to convert moles of \( \text{H}_2 \) to moles of \( \text{Fe} \) using the balanced equation, then convert moles of \( \text{Fe} \) to mass using the molar mass of iron (55.85 g/mol).

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이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
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10m

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 reactants and products in a chemical reaction. It allows us to calculate the amount of substances consumed and produced in a reaction based on balanced chemical equations. In this case, understanding stoichiometry is essential to determine how much iron is needed to produce a specific volume of hydrogen gas.
추천 영상:
가이드 코스
01:16
Stoichiometry Concept

Ideal Gas Law

The Ideal Gas Law is a fundamental equation in chemistry that relates the pressure, volume, temperature, and number of moles of a gas. It is expressed as PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the ideal gas constant, and T is temperature in Kelvin. This law is crucial for calculating the volume of hydrogen gas produced at a given temperature and pressure, which is necessary for solving the problem.
추천 영상:
가이드 코스
01:15
Ideal Gas Law Formula

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is used to convert between the mass of a substance and the number of moles. In this question, knowing the molar mass of iron (approximately 55.85 g/mol) is important for calculating how many kilograms of iron are required to produce the desired volume of hydrogen gas.
추천 영상:
가이드 코스
02:11
Molar Mass Concept
관련 실천
교과서 질문

Magnesium can be used as a “getter” in evacuated enclosures to react with the last traces of oxygen. (The magnesium is usually heated by passing an electric current through a wire or ribbon of the metal.) If an enclosure of 0.452 L has a partial pressure of O2 of 3.5×10−6 torr at 27°C, what mass of magnesium will react according to the following equation?

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교과서 질문

Calcium hydride, CaH2, reacts with water to form hydrogen gas:


CaH2(𝑠)+2 H2O(𝑙)⟶Ca(OH)2(𝑎𝑞)+2 H2(𝑔)

This reaction is sometimes used to inflate life rafts, weather balloons, and the like, when a simple, compact means of generating H2 is desired. How many grams of CaH2 are needed to generate 145 L of H2 gas if the pressure of H2 is 825 torr at 21°C?

교과서 질문

Consider the apparatus shown in the following drawing. (a) When the valve between the two containers is opened and the gases are allowed to mix, what is the partial pressure of N2 after mixing?

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교과서 질문

Consider the apparatus shown in the following drawing. (a) When the valve between the two containers is opened and the gases are allowed to mix, how does the volume occupied by the N2 gas change?

683
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