2NaHCO3(s) ⇌ Na2CO3(s) + CO2(g) + H2O(g) Kp 0.23

Sodium carbonate, Na2CO3(s), can be prepared

by heating sodium bicarbonate, NaHCO3(s).

2NaHCO3(s) ⇌ Na2CO3(s) + CO2(g) + H2O(g) ... Kp = 0.23 at 100℃

If a sample of NaHCO3 is placed in an evacuated flask

and allowed to achieve equilibrium at 100℃,

what will the total gas pressure be?

a) 0.46 atm

b) 0.96 atm

c) 0.23 atm

d) 0.48 atm

e) 0.11 atm

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2NaHCO3(s) ⇌ Na2CO3(s) + CO2(g) + H2O(g)

Kp = (P_CO2) (P_H2O)

( 참고 https://ywpop.tistory.com/7136 )

0.23 = (x) (x) = x^2

x = 0.23^(1/2) = 0.48

x = P_CO2 = P_H2O = 0.48 atm 이므로,

total gas pressure를 계산하면,

P_CO2 + P_H2O = 0.96 atm

답: b) 0.96 atm

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