Answer:
D. 9.
Explanation:
Mass number of an atom is the sum of the proton number and neutron number. For Be, the protons are 4 and neutrons are 5. So, we get 9 by adding them.
Decreasing the activation energy needed for the reaction.
Answer:
Theoretical yield
Explanation:
The theoretical yield of a product obtained from a reaction is the maximum obtainable amount of product from the reaction under ideal conditions and if all the limiting reactant is used up in the reaction. the actual yield however is lower a little than the theoretical yield in value
Answer:
![Kc=0.14](https://tex.z-dn.net/?f=Kc%3D0.14)
Explanation:
Hello,
In this case, for the given reaction, the equilibrium expression is:
![Kc=\frac{[NO]^2[O_2]}{[NO_2]^2}](https://tex.z-dn.net/?f=Kc%3D%5Cfrac%7B%5BNO%5D%5E2%5BO_2%5D%7D%7B%5BNO_2%5D%5E2%7D)
That in terms of the reaction extent
is written as (initial concentration of NO2 is 0.24 M for 0.24 mol in 1.00 L):
![Kc=\frac{(2*x)^2(x)}{(0.24M-2*x)^2}](https://tex.z-dn.net/?f=Kc%3D%5Cfrac%7B%282%2Ax%29%5E2%28x%29%7D%7B%280.24M-2%2Ax%29%5E2%7D)
Moreover, since at the equilibrium 0.14 moles of NO are present (a 0.14-M concentration), we can compute the reaction extent as shown below:
![[NO]=2*x=0.14M](https://tex.z-dn.net/?f=%5BNO%5D%3D2%2Ax%3D0.14M)
![x=0.14M/2=0.07M](https://tex.z-dn.net/?f=x%3D0.14M%2F2%3D0.07M)
In such a way, knowing
, we compute Kc as shown below:
![Kc=\frac{(2*0.07)^2(0.07)}{(0.24M-2*0.07)^2}\\\\Kc=0.14](https://tex.z-dn.net/?f=Kc%3D%5Cfrac%7B%282%2A0.07%29%5E2%280.07%29%7D%7B%280.24M-2%2A0.07%29%5E2%7D%5C%5C%5C%5CKc%3D0.14)
Regards.