Answer:
The pH changes by 2.0 if the [A-]/[HA] ratio of a base/weak acid mixture changes from 10/1 to 1/10.
Explanation:
To solve this problem we use the<em> Henderson-Hasselbach equation</em>:
Let's say we have a weak acid whose pKa is 7.0:
If the [A⁻]/[HA] ratio is 10/1, we're left with:
Now if the ratio is 1/10:
The difference in pH from one case to the other is (8.0-6.0) 2.0.
<em>So the pH changes by 2.0</em> if the [A-]/[HA] ratio of a base/weak acid mixture changes from 10/1 to 1/10.
<u>Keep in mind that no matter the value of pKa, the answer to this question will be the same.</u>
Answer: Magnesium
Explanation:
Galvanic cell is a device which is used for the conversion of the chemical energy produces in a redox reaction into the electrical energy.
The standard reduction potential for magnesium and zinc are as follows:
![E^0_{[Mg^{2+}/Mg]}= -2.37V](https://tex.z-dn.net/?f=E%5E0_%7B%5BMg%5E%7B2%2B%7D%2FMg%5D%7D%3D%20-2.37V)
![E^0_{[Zn^{2+}/Zn]}=-0.76V](https://tex.z-dn.net/?f=E%5E0_%7B%5BZn%5E%7B2%2B%7D%2FZn%5D%7D%3D-0.76V)
Reduction takes place easily if the standard reduction potential is higher (positive) and oxidation takes place easily if the standard reduction potential is less (more negative).
Here Mg undergoes oxidation by loss of electrons, thus act as anode. Zinc undergoes reduction by gain of electrons and thus act as cathode.


Thus magnesium gets oxidized.
32L —> 32000g —> 727.116 Moles (rounded)
Should be B, because one rotation is a day one revolution is a day(also to check I looked up the difference).