If a sample of NaHCO3(s) is brought to a temperature of 100oC in a closed container total gas pressure at equilibrium is:
Given,
Kp=0.23
ΔH∘=136kJ
The reaction given is 2NaHCO3(s)⇌Na2CO3(s)+CO2(g)+H2O(g)
Now we know that Kp for the above given reaction can be given as Kp=(PCO2)1×(PH2O)1 , since only H2O and CO2 are present in gaseous states. Now substituting, the value of Kpin the equation we get,
Kp=(PCO2)1×(PH2O)1
0.23=(PCO2)1×(PH2O)1
Also, since moles of H2O and CO2 are the same, the partial pressures will also be the same. Let that partial pressure be P .
Substituting the values in the formula we get,
P2=0.23
Taking the square root on both sides,
P=0.479
Total gas pressure will then be =PCO2+PH2O=2P
⇒2×0.479
⇒0.958atm≈0.96atm
Hence, the correct answer will be option A