Please help out with this, thank you! All the ksp and deltaG with both questions

Question

Please help out with this, thank you! All the ksp and deltaG with both questions below the chart.

Complete the following table of data for Na2HAsO4. (Assume the density of water is 1.00 g/mL.) T (oC) Solubility Concentration (g/100. g) (kJ/mol) 24.0 31.341.68 34.041,142.21 44.0 54.0 64.0 70.7 43.80 74.0 84.0 4.0 12.74 4.0 4.0 51.0 4.0 4.0 60.8 14 3.27 4.0 4.0 4.0 80.5 404.33 90.4 4.0 4.86 4.0 Use a graph of AG vs. T to determine the following. (Enter your answers to three significant figures.) What is the value of H for the system? kJ/mol What is the value of S for the system? J/mol.K

Explanation / Answer

sample calculation is done and rest of the calculation for solubility and solubility product are done in excel

molar mass of Na2HAsO4=186 g/mole, moles -mass /molar mass

at 24 deg.c, solubility is 31.3 gm/100 gm

100 gm of water contains 31.3 gm of Na2HASO4= 31.3/186 moles of Na2HASO4=0.168

density of water =1 g/ml, volume of water = 100*1=100ml, volume of water =(100/1000)L=0.1L

concentration of Na2HASO4= moles/volume in L= 0.168/0.1= 1.68 M

Na2HASO4 ionizes as Na2HASO4--------> 2Na+1+ HASO4-2

[Na+]= 2*1.68= 3.36M, [HASO4-2]= 1.68

KSp = [Na+]2 [HASO4-2] = 3.4*3.4*1.7= 19.06

The data on other temperatures is calculated and shown in excel.

deltaG= -RTlnKSp, T in K and R= 8.314 J/mole.K, these calculations at different temperatures are shown below

but deltaG= deltaH-T*deltaS

-RTlnKSp= deltaH-T*deltaS

lnKSP= -deltaH/RT+deltaS/R

so a plot of lnKSp vs 1/T gives straifght line whose slope is -deltaH/R and intercept is deltaS/R

the plot of lnKsp vs 1/T is generated and shown below with the data points.

from the plot, the slope is -deltaH/R= -5552.2, deltaH= 5552.2*8.314 J/mole =46161 J/mole= 46.161 KJ/mole

deltaS/R= 21.81 , intercept , deltaS= 21.81*8.314=181.32 J/mol.K

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