Answer: 
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)

Putting in the values:

![5.29=-log[H^+]](https://tex.z-dn.net/?f=5.29%3D-log%5BH%5E%2B%5D)
![[H^+]=5.1\times 10^{-6}](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D5.1%5Ctimes%2010%5E%7B-6%7D)
Thus
is 
Missing table!! write the elements with the first letter of the symbol with Upper Caps letters!!!
http://www.chemeddl.org/services/moodle/media/QBank/GenChem/Tables/EStandardTable.htm
<span>Ni2+ +Pb(s) → Ni(s) + Pb2+
</span>The potential of the oxidation of Pb(s) --> Pb2+(aq) is 0.126 V
The potential of the reduction go Ni2+(aq) --> Ni(s) is -0.25 V
<span>Add the two together and the potential for the reaction is -0.124 V (NO SPONTANEOUS THE SIGN IS NEGATIVE)
</span><span>au3+ + al(s) → au(s) + al3+Au3+(aq) -> Au(s) +1.5 VAl -> Al3+ +1.66VV= 3.16 (SPONTANEOUS THE SIGN OF THE PONTENTIAL IS POSITIVE)</span><span>Sr2+ + Sn(s) → Sr(s) + Sn2+
</span>
Sr2+(aq) + 2 e– <span> Sr(s) V= -2.89V
</span>Sn -> Sn2+ V= 0.14 V
V= -2.75 V (no spontaneous)
<span>Fe2+ + Cu(s) → Fe(s) + Cu2+
</span>Fe2+(aq) + 2 e–<span> </span><span> Fe(s) V= -0.44 V
</span>Cu -> C2+ V = - 0.337V
V= - 0.777V (no spontaneous)
Answer:
C. 70%
Explanation:
Atomic Mass of the silicon = 28 g.
Atomic mass of the Carbon = 12 g.
Total mass of the Silicon Carbide = 28 + 12
= 40 g.
Now, Using the formula.
% Composition = Mass of the silicon/Total mass of the compound × 100 %
= 28/40 × 100 %
= 70 %
Hence, % composition of the silicon in SiC is 70%