Answer:
<em>Valency is the combining power of an element. Elements in the same group of the periodic table have the same valency. The valency of an element is related to how many electrons are in the outer shell. The noble gases have the valency 0 as they do not usually combine with other elements.</em>
Explanation:
HOPE IT HELPS
Rate law for the given 2nd order reaction is:
Rate = k[a]2
Given data:
rate constant k = 0.150 m-1s-1
initial concentration, [a] = 0.250 M
reaction time, t = 5.00 min = 5.00 min * 60 s/s = 300 s
To determine:
Concentration at time t = 300 s i.e. ![[a]_{t}](https://tex.z-dn.net/?f=%5Ba%5D_%7Bt%7D)
Calculations:
The second order rate equation is:
![1/[a]_{t} = kt +1/[a]](https://tex.z-dn.net/?f=1%2F%5Ba%5D_%7Bt%7D%20%3D%20kt%20%2B1%2F%5Ba%5D)
substituting for k,t and [a] we get:
1/[a]t = 0.150 M-1s-1 * 300 s + 1/[0.250]M
1/[a]t = 49 M-1
[a]t = 1/49 M-1 = 0.0204 M
Hence the concentration of 'a' after t = 5min is 0.020 M
Answer:
Standard free-energy change at
is 
Explanation:
Oxidation: 
Reduction: 
--------------------------------------------------------------------------------------
Overall: 
Standard cell potential, 
So, 
We know, standard free energy change at
(
): 
where, n is number of electron exchanged during cell reaction, 1F equal to 96500 C/mol
Here n = 2
So, 
Answer:
it is endothermic change ..........