For a solid-state transformation that obeys the Avrami equation, the parameter n has been determined to have a value of 1.5. The reaction takes 125 seconds to reach 30% completion. What is the total time (in seconds) for the transformation to reach 95% completion

Respuesta :

Answer:

The total time (in seconds) for the transformation to reach 95% completion is 516.783 secs

Explanation:

Given Data:

n=1.5

Time to reach 30% completion=125 Secs

Required:

Total Time  for the transformation to reach 95% completion=?

Solution:

Avrami Equation:

[tex]y=1-e^{-kt^n}[/tex]

where:

k is time constant

t is the time

y is the remaining amount of reaction.

First Calculate K:

[tex]0.3-1=-e^{-k*125^1.5}\\-0.7=-e^{-k*125^1.5}\\[/tex]

Taking "ln"on both sides

ln(0.7)=-k*(125^1.5)

k=0.000255

At 95 % completion:

Avrami Equation Can be rearranged as:

[tex]y-1=-e^{-kt^n}\\ln(-y+1)=-k*t^n\\\frac{ln(-y+1)}{-k}=t^n\\ ln(\frac{ln(-y+1)}{-k})=n*lnt\\\frac{ln(\frac{ln(-y+1)}{-k})}{n}=lnt \\e^{\frac{ln(\frac{ln(-y+1)}{-k})}{n}}=t[/tex]

[tex]e^{\frac{ln(\frac{ln(-0.95+1)}{-0.000255}))}{1.5}}=t\\t=516.783 \ secs[/tex]

The total time (in seconds) for the transformation to reach 95% completion is 516.783 secs