Usando valores del apéndice C, calcule el cambio estándar de...

Usando valores del apéndice C, calcule el cambio estándar de entalpía para cada una de las reacciones siguientes: (a) $2 \mathrm{SO}_2(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g}) \longrightarrow 2 \mathrm{SO}_3(\mathrm{~g})$ (c) $4 \mathrm{FeO}(\mathrm{s})+\mathrm{O}_2(\mathrm{~g}) \longrightarrow 2 \mathrm{Fe}_2 \mathrm{O}_3(\mathrm{~s})$ (d) $\mathrm{SiCl}_4(l)+2 \mathrm{H}_2 \mathrm{O}(l) \longrightarrow \mathrm{SiO}_2(s)+4 \mathrm{HCl}(g)$

Usando valores del apéndice C, calcule el cambio estándar de entalpía para cada una de las reacciones siguientes:
(a) $2 \mathrm{SO}_2(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g}) \longrightarrow 2 \mathrm{SO}_3(\mathrm{~g})$
(c) $4 \mathrm{FeO}(\mathrm{s})+\mathrm{O}_2(\mathrm{~g}) \longrightarrow 2 \mathrm{Fe}_2 \mathrm{O}_3(\mathrm{~s})$
(d) $\mathrm{SiCl}_4(l)+2 \mathrm{H}_2 \mathrm{O}(l) \longrightarrow \mathrm{SiO}_2(s)+4 \mathrm{HCl}(g)$

Key Concepts

Standard Enthalpy of Formation

This concept refers to the heat change that occurs when one mole of a compound is formed from its constituent elements in their standard states. It is a fundamental property used in thermochemistry to quantify how much energy is stored in chemical bonds, and it forms the basis for calculating reaction enthalpies using tabulated values.

Hess's Law

Hess's Law states that the total enthalpy change for a reaction is independent of the pathway taken, meaning it can be calculated by summing the standard enthalpies of formation of the products and subtracting the sum of the standard enthalpies of formation of the reactants. This principle allows chemists to determine enthalpy changes for reactions that may be difficult to measure directly.

Stoichiometry in Thermochemical Calculations

This involves using the balanced chemical equation to account for the proportions of reactants and products when calculating overall energy changes. The stoichiometric coefficients multiply the standard enthalpy values, ensuring that the calculated enthalpy change accurately reflects the amounts of substances involved in the reaction.

Transcript

Please give Ace some feedback