The majority of an atoms' mass comes from the protons and neutrons that make up its nucleus.
Answer:
The pH of the final solution is 7.15
Explanation:
50 mL of 2.0 M of
and 25 mL of 2.0 M of
were mixed to make a solution
Final volume of the solution after dilution = 200 mL
Final concentration of ![K_2HPO_4, [K_2HPO_4] = \frac{50 mL\times 2 M}{200 mL} = 0.5 M](https://tex.z-dn.net/?f=K_2HPO_4%2C%20%5BK_2HPO_4%5D%20%3D%20%5Cfrac%7B50%20mL%5Ctimes%202%20M%7D%7B200%20mL%7D%20%3D%200.5%20M)
Final concentration of![KH_2PO_4, [KH_2PO_4] = \frac{25 mL\times 2 M}{200 mL} = 0.25 M](https://tex.z-dn.net/?f=KH_2PO_4%2C%20%5BKH_2PO_4%5D%20%3D%20%5Cfrac%7B25%20mL%5Ctimes%202%20M%7D%7B200%20mL%7D%20%3D%200.25%20M)
We use Hasselbach- Henderson equation:
![pH = pK_a+ log \frac{[salt]}{[acid]}pka of KH_2PO_4 = 6.85](https://tex.z-dn.net/?f=pH%20%3D%20pK_a%2B%20log%20%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7Dpka%20of%20KH_2PO_4%20%3D%206.85)
Substituting the values:

Therfore, the pH of the final solution is 7.15
Answer:
(a) Two electrochemical half reactions for ethanol
is written below
⇒ 
⇒

(b) The direct oxidation of the fuel will occur in a solid oxide fuel cell but we have to compete with other sets of chemical electrochemical reaction such as water-gas-shift reaction
⇆ 
(c) The electrochemical half reaction that could convert ethanol directly into a fuel cell that conducts hydrogen ions is shown below
⇒ 

⇒ 
(d) The half reactions that would be required are shown below
⇒ 
⇒ 
⇒ 