Consider the decomposition of the compound C5H6O3 as follows below. C5H6O3(g) → C2H6(g) + 3 CO(g) When a 5.63-g sample of pure C5H6O3(g) was sealed into an otherwise empty 2.50 L flask and heated to 200.°C, the pressure in the flask gradually rose to 1.63 atm and remained at that value. Calculate K for this reaction.

K = 6.5 × 10⁻⁶

Explanation:

C₅H₆O₃(g) → C₂H₆(g) + 3 CO(g)

The formula for the ideal gas law

PV = nRT

where

P = total pressure

V = volume

n = total moles

R = gas constant

T = absolute temperature

P(C₅H₆O₃) = nRT/V

where

n = 5.63 /114

= 0.049

=

C₅H₆O₃(g) ⇄ C₂H₆(g) + 3 CO(g)

0.78atm           0              0

0.78 - x            x              3x

P(total) = 1.63atm

0.78atm - x + x + 3x⇒x = 0.288atm

P(C₅H₆O₃)  = 0.78 - 0.288

                  = 0.489 atm

P(C₂H₆)  = 0.288 atm

P(CO) = 0.846 atm

= 0.379

K = Kp/(RT³)

K = 6.5 × 10⁻⁶

answer carbon and three oxygen atoms;