Calculate NaHCO3 Molar Mass & Equilibrium Constants

[gtfish]

Here's the question (ANY tips or help would be great):

Given equation- 2NaHCO3(s)<-->Na2CO3(s)+H2O(g)+CO2(g)
a. A sample of 100 grams of solid NaHCO3 was placed in an 5 L container and heated to 160 degrees C. Some of the original solid remained and the total pressure in the container was 7.76 atmospheres when equilibrium was reached. Calculate the number of moles of H2O present at equilibrium. (NaHCO3 molar mass= 84 g, PV=nRT, R=.08206 L atm/mol K)
b. How many grams of the original solid remain in the container under the conditions described in "a"?
c.Write the equilibrium expression for the equilibrium constant Kp and calculate its value for the reaction under the conditions in "a".
d. If 115 g. of solid NaHCO3 had been placed in the 5 L container and heated to 160 degrees C, what would have the total pressure been at equilibrium?

 

[himanshu121]

The Total Pressure will be due to water vapours+CO₂
The individual pressure will be 7.76/2 . so u have partial pressure of H₂O U have its Volume And Temperature.
So u can calculate the no of mol of Water vapours by the eqn u have mentioned

For part (b)

u have initial no of mol of NaHCO₃ as 100/84

final no of mol= initial - 2*(no of mol of H2O) [? Why answer urself]

I believe it is better that u do the rest of the Parts/ Or show what u have tried so far on the problem