Metallic mercury is obtained by heating the mineral cinnabar (HgS) in air: HgS1s2 + O21g2 S Hg1l2 + SO21g2 (a) Use the data in Appendix B to calculate ΔH° in kilojoules for the reaction.

검증된 단계별 안내

Identify the chemical reaction: HgS(s) + O2(g) -> Hg(l) + SO2(g).

Use the standard enthalpy of formation (ΔH_f°) values from Appendix B for each compound involved in the reaction.

Calculate the total ΔH° for the products by summing the ΔH_f° values of Hg(l) and SO2(g).

Calculate the total ΔH° for the reactants by summing the ΔH_f° values of HgS(s) and O2(g).

Determine ΔH° for the reaction by subtracting the total ΔH° of the reactants from the total ΔH° of the products: ΔH° = ΣΔH_f°(products) - ΣΔH_f°(reactants).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

영상 길이:

주요 개념

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

Enthalpy Change (ΔH°)

Enthalpy change (ΔH°) is the heat content change of a system at constant pressure during a chemical reaction. It indicates whether a reaction is exothermic (releases heat, ΔH° < 0) or endothermic (absorbs heat, ΔH° > 0). Calculating ΔH° involves using standard enthalpy of formation values for reactants and products, which are typically found in thermodynamic tables.

Standard Enthalpy of Formation

The standard enthalpy of formation (ΔHf°) is the change in enthalpy when one mole of a compound is formed from its elements in their standard states. Each substance has a specific ΔHf° value, which is essential for calculating the overall ΔH° of a reaction. For elements in their standard state, ΔHf° is defined as zero.

Stoichiometry in Chemical Reactions

Stoichiometry involves the quantitative relationships between the amounts of reactants and products in a chemical reaction. It is crucial for balancing chemical equations and determining the moles of substances involved. In the context of calculating ΔH°, stoichiometry allows for the correct application of ΔHf° values based on the coefficients in the balanced equation.