Pure lead melts at 460/deg C. Given that the heat of fusion is 1750 cal/mol, calculate the entropy change of the surroundings during the transformation. Then determine the total entropy change basec on this.

When 1.87 g of a salt dissolves in 108 mL of water (density = 1.00 g/mL) in a coffee-cup calorimeter, the temperature rises from 19.5°C to 27.1°C. Determine q for the solution process, assuming that Ccal ~ Cwater. Include the mass of salt in your calculation.

Without doing any calculations, match the following thermodynamic properties with their appropriate numerical sign for the following endothermic reaction. CH4(g) + H₂O(g)—CO(g) + 3H₂(g) Hrxn Grxn ASrxn Suniverse > 0 0 low T, 0 high T Previous Next

Consider the reaction: 2 NO2 (g) = N204 (g) The standard-state enthalpies of formation (AHf) for NO2(g) and N204(g) are +33.2 and +9.2 kJ mol-1, respectively. The third law entropies (S°) for NO210) and N,04lg) are 240.1 and 98.0 J K-1 mol-1, respectively. a) What is the value of AG° for this reaction? b) What is the equilibrium constant (K) for the reaction at 25 °C? c) What is the value of K for the same reaction at -25 °C? d) What is AG for the reaction at 25 °C when both gases initially exist at 2.2 atm pressure?

When 5.12 g of a salt dissolves in 190. mL of water (density = 1.00 g/mL) in a coffee-cup calorimeter, the temperature rises from 17.0°C to 23.5°C. Determine q for the solution process, assuming that Ccal Cwater- Include the mass of salt in your calculation. kJ

5.000 g of aluminum (III) chloride is dissolved in 60.0 mL of water. The temperature changes by 0.331C. The specific heat capacity of aluminum (III) chloride is 0.903 ??∙°C. What is deltaHs?

ences to access important values if needed for this question. When 5.42 g of potassium bromide (KBr) is dissolved in 114g of water in a styrofoam calorimeter of negligible heat capacity, the temperature drops from 25.00 to 23.03 °C. Based on this observation, calculate q for the water and AH° for the process, assuming that the heat absorbed by the salt is negligible, KBr(s) K*(aq) + Br (aq) The specific heat of water is 4.184] °C¹g¹. Give the answers in kJ. ан, о AHO

Which of the following describes the second law of thermodynamics?deltaS(system) + deltaS (surroundings) <0deltaS (system) - deltaS (surroundings) = 0deltaS(system) - deltaS (surroundings) <0deltaS(system) - deltaS (surroundings) > 0deltaS(system) + deltaS (surroundings) = 0deltaS (system) + deltaS (surroundings) > 0

Enthalpy and Gibb's Free Energy Chemical energy is released or absorbed from reactions in various forms. The most easily measurable form of energy comes in the form of heat, or enthalpy. The enthalpy of a reaction can be calculated from the heats of formation of the substances involved in the reaction: AHxn = AH₂ (products) - AH (reactants) Entropy change, AS°, is a measure of the number of energetically equivalent microstates introduced into the system during the reaction. The degree of spontaneity of a reaction is represented by the Gibbs free energy, AGO. The Gibbs free energy depends on both the enthalpy and entropy changes that take place during the reaction: AG=AH° - TAS° where T is standard temperature, 298 K. ▼ Part A Calculate the standard enthalpy change for the reaction where the heats of formation are given in the following table: ΔΗ Substance (kJ/mol) A B C D -241 -407 191 -501 Express your answer in kilojoules. ► View Available Hint(s) {—| ΑΣΦ AHixn= 2A+B=2C+2D ? kJ…

1. A 50g sample of metal iron that was heated to 90 °C was dropped into a coffee cup calorimeter containing 200mL of water at room temperature of 25 °C. Applying the density of water (1g/mL) and specific heat capacity capacities of water and iron, determine the final temperature when the system reaches equilibrium.