Physical Chemistry Answers

The standard free energy of chemical reaction 2A + B ⇆ 2C at 500 K = 2 KJ mol-1. Calculate Kp at 500 K for the chemical reaction A + ½B ⇆ C.

Predict whether the following reaction is still spontaneous at 500C:

N2(g) + 3 H2(g) equilibr.gif (63 bytes) 2 NH3(g)

Assume that the values of deltaHo and deltaS used in the first Problem are still valid at this temperature.



Use the value of deltaGo obtained in the first Problem to calculate the equilibrium constant for the following reaction at 25C:

N2(g) + 3 H2(g) equilibr.gif (63 bytes) 2 NH3(g)

Calculate deltaH and deltaS for the following reaction and decide in which direction each of these factors will drive the reaction.

N2(g) + 3 H2(g) equilibr.gif (63 bytes) 2 NH3(g)



Calculate deltaH and deltaS for the following reaction:

NH4NO3(s) + H2O(l) ---> NH4+ (aq) + NO3- (aq)

Use the results of this calculation to determine the value of deltaGo for this reaction at 25o C, and explain why NH4NO3 spontaneously dissolves is water at room temperature.

A 2m long pipelines tapers uniformly form 10cm diameter to 20cm diameters at its upper end. The pipe centreline slopes upwards at a angle of 30° to the horizontal and the flow direction is from smaller to bigger cross section. If the pressure gauges installed at lower and upper ends of the pipeline read 200kpa and 230kpa respectively. Determine the flow rate and the pressure mid length of the pipeline. Assume no energy losses.

La + e → ?

Ethanoic acid and ethanol react reversibly to form ethyl ethanoate and water. (It doesn't matter if you have never come across this before.) In a closed system, a dynamic equilibrium is set up.ethanoic acid ethanolethyl ethanoatea) Suppose you now added some more ethanol. What effect would that have on the percentage of ethanoic acid converted into ethyl ethanoate. Explain your answer using Le Chatelier's Principle.b) This reaction is fairly slow, and is usually done in the presence of a small amount of concentrated sulphuric acid as a catalyst to speed it up.(i) What effect would that have on the percentage of ethanoic acid converted into ethyl ethanoate? Explain your answer.(ii) (You will need to think about this one! It isn't covered on the page you have just read, but it is still about Le Chatelier's Principle.) If you wanted to make as much ethyl ethanoate as possible, why would it be a bad idea to use dilute sulphuric acid as the catalyst

Calculate the number of pounds of CO2 released into the atmosphere when a 14.0 gallon tank of gasoline is burned in an automobile engine. Assume that gasoline is primarily octane, C8H18, and that the density of gasoline is 0.692 g⋅mL−1. This assumption ignores additives. Also, assume complete combustion.

using the equipartition of energy concept estimate the ideal gas Cp(not Cv) in units KB for the low temperature regime where no vibrational modes are activated(if you calculate Cp=42KB, enter 42 as your answer )