3. [4/8 Points] DETAILS PREVIOUS ANSWERS A container of 3.2 mol of gas expands from 1.5 L to 2.5 L (1 L = 0.001 m ) while the pressure is kept constant. The gas is initially at a temperature of 300 K. What is the pressure of the gas? P = 5.32x10^6 Pa What is the final temperature of the gas? T1 = 500 What is the magnitude of the change in internal energy of the gas, and is the internal energy increasing or decreasing? (Note that there is no change in chemical energy because there is no reaction that occurs.) IAUintl = J, Increasing What is the magnitude of the energy transferred as work, and is it transferred into or out of the gas? IWI = C J, Out of the gas V What is the magnitude of the energy transferred as heat, and is it transferred into or out of the gas? 1Q1 = 3, Into the gas Viewing Saved Work Revert to Last Response 4. [9/10 Points] DETAILS PREVIOUS ANSWERS Consider the reaction 2H2(9) + Oz(g) - 2H20(9) The following bond energies have been determined experimentally: H-H 436 kJ/mo 0=0 497 k.Jmol H-O 464 kJ/mol A. Suppose we start with 4 mol of hydrogen. How many moles of oxygen are needed to "use up" all of the hydrogen? How many moles of water molecules are produced? n of Oz = 2 n of H20 = 4 B. For the number of moles in part A, what is the difference in chemical energy between the reactants and the products for this reaction? (Give the absolute value only.) 14Echem| - 974 KJ C. Does your answer to part B represent a net input of energy, or a net release of energy if the reaction proceeds in the direction indicated? Does the chemical energy increase, or decrease? There is a net [ release v v of energy, and the chemical energyInment-Responses/submit?dep=30867371&tags=autosave#Q2 2. [2/4 Points] DETAILS PREVIOUS ANSWERS A small amount of heat Q flows out of a hot system A (at Thot = 360 K) into a cold system B (at 7cold = 225 K). The overall [AB] system is thermally isolated from the rest of the universe. (Q is small enough that the temperature - 350 K and 7cold = 250 K -- do not use the temperatures in the figure). 1. Do you expect the entropy change of the [AB] system to be positive, negative, or zero? positive Explain why you think so. Entropy is changed due to heat interaction between a mathematical explanation is given Score: 1 out of 1 Comment: 2. If Q = 1 J, mA = 1.2 kg, and my = D.6 kg, find the total change in the entropy of the [AB] system, ASAB- ASAB - J/K 3. Suppose we let the two objects come to a thermal equilibrium. Do you expect the total Gibbs free energy of the [AB] system to have increas ained the same? ---Select- Explain why you think so. This answer has not bean graded yet 3. [9/9 Points] DETAILS PREVIOUS ANSWERS Photosynthesis is the process by which plants effectively capture energy from the sun and store it for later use by organisms. It's the fundamental process that enables the entire food chain. Actual photosynthesis is a highly complex p (enthalpy, Gibbs free energy, and entropy) using simpler reactions. Let's consider a toy model in which an input of energy (for example from the sun) is be used to combine water and carbon dioxide to create an organic molecule (formaldehyde) and oxygen, effectively "storing" that energy for use later CO2 + H20 7 02 + CH20 The table lists the enthalpy of formation, AH, and the entropy S for 1 mol of each of the substances involved in this reaction at 298 K and 105 pa. AH()S (3/K) CH20 -115.9 0.2189MY NOT ANSWERS system A (at Thot = 360 K) into a cold system B (at Tcold = 225 K). The overall [AB] system is thermally isolated from the rest of the universe. (Q is small enough that the temperature changes of the objects can be ignored.) The figure shows an example of this process (but with hot temperatures in the figure). AB ] system to be positive, negative, or zero? 350K 250K on a and B mathematical explanation is given 9, find the total change in the entropy of the [AB] system, ASAB- a thermal equilibrium. Do you expect the total Gibbs free energy of the [AB] system to have increased, decreased, or remained the same? V US ANSWERS MY NOTES y) using simpler reactions. plants effectively capture energy from the sun and store it for later use by organisms. It's the fundamental process that enables the entire food chain. Actual photosynthesis is a highly complex process involving many steps and many different chemicals, but we can get an idea of what's happening to thermodynamic quantities input of energy (for example from the sun) is be used to combine water and carbon dioxide to create an organic molecule (formaldehyde) and oxygen, effectively "storing" that energy for use later. The simplest possible such process is given by: , AH, and the entropy S for 1 mol of each of the substances involved in this reaction at 298 K and 105 pa. ning that 1 mol of formaldehyde molecules are formed. this reaction? m = 109 'nm 1 km = 10oom, Jmeans h = 6.63 x 10:34 5 -xy .m Im = 10 12 pm