Answer:
rate of recrystallization = 4.99 × 10⁻³ min⁻¹
Explanation:
For Avrami equation:
To calculate the value of k which is a dependent variable for the above equation ; we have:
The time needed for 50% transformation can be determined as follows:
![y = 1-e ^{(-kt^n)} \\ \\ e^{(-kt^n)} = 1-y\\ \\ -kt^n = In(1-y) \\ \\ t =[ \dfrac{-In(1-y)}{k}]^{^{1/n}}](https://tex.z-dn.net/?f=y%20%3D%201-e%20%5E%7B%28-kt%5En%29%7D%20%5C%5C%20%5C%5C%20e%5E%7B%28-kt%5En%29%7D%20%3D%201-y%5C%5C%20%5C%5C%20-kt%5En%20%3D%20In%281-y%29%20%5C%5C%20%5C%5C%20t%20%3D%5B%20%5Cdfrac%7B-In%281-y%29%7D%7Bk%7D%5D%5E%7B%5E%7B1%2Fn%7D%7D)
![t_{0.5} =[ \dfrac{-In(1-0.4)}{9.030 \times 10^{-7}}]^{^{1/2.5}}](https://tex.z-dn.net/?f=t_%7B0.5%7D%20%3D%5B%20%5Cdfrac%7B-In%281-0.4%29%7D%7B9.030%20%5Ctimes%2010%5E%7B-7%7D%7D%5D%5E%7B%5E%7B1%2F2.5%7D%7D)
= 200.00183 min
The rate of reaction for Avrami equation is:
rate = 0.00499 / min
rate of recrystallization = 4.99 × 10⁻³ min⁻¹
Answer:
The answer to your questions is Cm = 25.5 J/mol°C
Explanation:
Data
Heat capacity = 0.390 J/g°C
Molar heat capacity = ?
Process
1.- Look for the atomic number of Zinc
Z = 65.4 g/mol
2.- Convert heat capacity to molar heat capacity
(0.390 J/g°C)(65.4 g/mol)
- Simplify and result
Cm = 25.5 J/mol°C
An exponential decay law has the general form: A = Ao * e ^ (-kt) =>
A/Ao = e^(-kt)
Half-life time => A/Ao = 1/2, and t = 4.5 min
=> 1/2 = e^(-k*4.5) => ln(2) = 4.5k => k = ln(2) / 4.5 ≈ 0.154
Now replace the value of k, Ao = 28g and t = 7 min to find how many grams of Thalium-207 will remain:
A = Ao e ^ (-kt) = 28 g * e ^( -0.154 * 7) = 9.5 g
Answer 9.5 g.
