The gas-phase decomposition of ch3cho (g) occurs according to the equation
ch3cho (g) > ch4 (g) +co (g) and is second order. the value of the rate constant is 0.105 m-1 x s-1 at 490 degrees celcius. if the concentration of ch3cho (g) is 0.012 m initially, what will be its concentration 5.0 minutes later.

Concentration of CH3CHO  5.0 minutes later is

M or 0.00871 M

Explanation:

The concentration for second order reaction can be calculated using the formula:

Here , [A] = Concentration of substance at time t

t = time

= Initial concentration

k = rate constant

According to question :

[A]  = Concentration of CH3CHO at time 5.0s = ?

= 0.012 M

t = 5.0 min

Convert it into second (because rate constant units are in second)

1 min = 60 s

t = 5 x 60 = 300 s

k = 0.105 M-1 s-1

Insert these value into,

M

Hence ,concentration of CH3CHO  5.0 minutes later is

M or 0.00871 M

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