Answer:
a) Q = 251.758 kJ/mol
b) creep rate is 
Explanation:
we know Arrhenius expression is given as
where
Q is activation energy
C is pre- exponential constant
At 700 degree C creep rate is
% per hr
At 800 degree C creep rate is
% per hr
activation energy for creep is 
= 
![\frac{1\%}{5.5 \times 10^{-2}\%} = e^{[\frac{-Q}{R(800+273)}] -[\frac{-Q}{R(800+273)}]}](https://tex.z-dn.net/?f=%5Cfrac%7B1%5C%25%7D%7B5.5%20%5Ctimes%2010%5E%7B-2%7D%5C%25%7D%20%3D%20e%5E%7B%5B%5Cfrac%7B-Q%7D%7BR%28800%2B273%29%7D%5D%20-%5B%5Cfrac%7B-Q%7D%7BR%28800%2B273%29%7D%5D%7D)
![\frac{0.01}{5.5\times 10^{-4}} = ln [e^{\frac{Q}{8.314}[\frac{1}{1073} - \frac{1}{973}]}]](https://tex.z-dn.net/?f=%5Cfrac%7B0.01%7D%7B5.5%5Ctimes%2010%5E%7B-4%7D%7D%20%3D%20ln%20%5Be%5E%7B%5Cfrac%7BQ%7D%7B8.314%7D%5B%5Cfrac%7B1%7D%7B1073%7D%20-%20%5Cfrac%7B1%7D%7B973%7D%5D%7D%5D)
solving for Q we get
Q = 251.758 kJ/mol
b) creep rate at 500 degree C
we know
Answer:
Time of submersion in years = 7.71 years
Explanation:
Area of plate (A)= 16in²
Mass corroded away = Weight Loss (W) = 3.2 kg = 3.2 x 106
Corrosion Penetration Rate (CPR) = 200mpy
Density of steel (D) = 7.9g/cm³
Constant = 534
The expression for the corrosion penetration rate is
Corrosion Penetration Rate = Constant x Total Weight Loss/Time taken for Weight Loss x Exposed Surface Area x Density of the Metal
Re- arrange the equation for time taken
T = k x W/ A x CPR x D
T = (534 x 3.2 x 106)/(16 x 7.9 x 200)
T = 67594.93 hours
Convert hours into years by
T = 67594.93 x (1year/365 days x 24 hours x 1 day)
T = 7.71 years
Answer:
Im pretty sure the answer is B
Explanation:
Paul will need to persuade his client of the benefits of the different filter.
Answer:
George Washington was the first president
