I tried calculating the Ksp as 4(M)^3 and that did NOT work Complete the followi

Question

I tried calculating the Ksp as 4(M)^3 and that did NOT work

Complete the following table of data for Ba(NO3)2. (Assume the density of water is 1.00 g/mL.) T (°C) Solubility (g/100. g) Concentration K. AG (kJ/mol) sp 12.1 4.0.462 13.5 490.516 14.9 | 0.570 16.4 40.627 35.0 40.0 18.0 4.0.68 40.746 60.021.2 400.811 55.0 19.5 Use a graph of AG vs. T to determine the following. (Enter your answers to three significant figures.) for the system? kJ/mol What is the value of What is the value of S for the system? J/mol-K

Explanation / Answer

molar mass of Ba(NO3)2 =261 g/mole

moles of Ba(NO3)2 = 12.1/261=0.04636

this moles are available in 100 gm of water. Density of water= 1g/ml, volume of water =100 gm/1gm/ml= 100ml= 100/1000 =0.1 L

Concentration of Ba(NO3)2= 0.04636/0.1= 0.463M

Ba(NO3)2 --------> Ba+2 + 2NO3-

KSp = [Ba+2] [NO3-]2 = (0.463)*(2*0.463) 2=   4*(0.463)3=0..397

the calculations for other solubility is also shown in the excel sheet.

for calculating deltaG, = -RT lnKSp

so a table of delta G is also created.   R= 8.314 J/mole.K or 8.314/1000 Kj/mole.K

This table is shown below

deltaG= deltaH- T*deltaS

-RT lnKSp = deltaH- T*deltaS

lnKSp = -deltaH/RT + deltaS/R

so a plot of lnKSp vs 1/T ( T in K) gives slope of -deltaH/R and intercept of deltaS/R

-deltaH/R= -5642.7, deltaH= 5642.7*8.314 J/mole =46913.4 J/mole= 46.913 Kj/mole

deltaS/R= 17.724 intercept

deltaS= 17.724*8.314 J/mole =147.4 J/mole.K

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