Answer:
1. The pH of 1.0 M trimethyl ammonium (pH = 1.01) is lower than the pH of 0.1 M phenol (5.00).
2. The difference in pH values is 4.95.
Explanation:
1. The pH of a compound can be found using the following equation:
![pH = -log([H_{3}O^{+}])](https://tex.z-dn.net/?f=%20pH%20%3D%20-log%28%5BH_%7B3%7DO%5E%7B%2B%7D%5D%29%20)
First, we need to find [H₃O⁺] for trimethyl ammonium and for phenol.
<u>Trimethyl ammonium</u>:
We can calculate [H₃O⁺] using the Ka as follows:
(CH₃)₃NH⁺ + H₂O → (CH₃)₃N + H₃O⁺
1.0 - x x x
![Ka = \frac{[(CH_{3})_{3}N][H_{3}O^{+}]}{[(CH_{3})_{3}NH^{+}]}](https://tex.z-dn.net/?f=Ka%20%3D%20%5Cfrac%7B%5B%28CH_%7B3%7D%29_%7B3%7DN%5D%5BH_%7B3%7DO%5E%7B%2B%7D%5D%7D%7B%5B%28CH_%7B3%7D%29_%7B3%7DNH%5E%7B%2B%7D%5D%7D)
![10^{-pKa} = \frac{x*x}{1.0 - x}](https://tex.z-dn.net/?f=%2010%5E%7B-pKa%7D%20%3D%20%5Cfrac%7Bx%2Ax%7D%7B1.0%20-%20x%7D%20)
By solving the above equation for x we have:
x = 0.097 = [H₃O⁺]
<u>Phenol</u>:
C₆H₅OH + H₂O → C₆H₅O⁻ + H₃O⁺
1.0 - x x x
![Ka = \frac{[C_{6}H_{5}O^{-}][H_{3}O^{+}]}{[C_{6}H_{5}OH]}](https://tex.z-dn.net/?f=Ka%20%3D%20%5Cfrac%7B%5BC_%7B6%7DH_%7B5%7DO%5E%7B-%7D%5D%5BH_%7B3%7DO%5E%7B%2B%7D%5D%7D%7B%5BC_%7B6%7DH_%7B5%7DOH%5D%7D)
![10^{-10} = \frac{x^{2}}{1.0 - x}](https://tex.z-dn.net/?f=%2010%5E%7B-10%7D%20%3D%20%5Cfrac%7Bx%5E%7B2%7D%7D%7B1.0%20-%20x%7D%20)
![1.0 \cdot 10^{-10}(1.0 - x) - x^{2} = 0](https://tex.z-dn.net/?f=%201.0%20%5Ccdot%2010%5E%7B-10%7D%281.0%20-%20x%29%20-%20x%5E%7B2%7D%20%3D%200%20)
Solving the above equation for x we have:
x = 9.96x10⁻⁶ = [H₃O⁺]
![pH = -log([H_{3}O^{+}]) = -log(9.99 \cdot 10^{-6}) = 5.00](https://tex.z-dn.net/?f=%20pH%20%3D%20-log%28%5BH_%7B3%7DO%5E%7B%2B%7D%5D%29%20%3D%20-log%289.99%20%5Ccdot%2010%5E%7B-6%7D%29%20%3D%205.00%20)
Hence, the pH of 1.0 M trimethyl ammonium is lower than the pH of 0.1 M phenol.
2. The difference in pH values for the two acids is:
Therefore, the difference in pH values is 4.95.
I hope it helps you!
Stars with higher mass have much shorter life cycles because stars expand as they get older that is why the larger the star the older it is smaller stars are more dense with more energy
Answer:
C: The shape of the pebbles is a result of weathering and deposition
Explanation:
For the several pebbles to have a rounded shape and smooth to the touch, it will undergo weathering and deposition. This is because weathering involves breaking down of rocks and creating new sediments. This weathering could be either chemical weathering or physical weathering where Chemical weathering is the decomposition of rocks which are caused by chemical reactions and which result in formation of new compound while physical weathering is the breakdown of rocks into smaller pieces. On the other hand, deposition occurs when the agents of erosion such as wind or water deposit sediments from one spot to another which in turn changes the shape of the land.
Thus, the shape of the pebbles are as a result weathering of the parent rocks and from deposition.
Answer:
m=621.54g
Explanation:
number of moles= mass of H2O/molar mass of H2O
n=m/mm
make mass the subject of the formula
m=n*mm
find molar mass of water
H2O=1(16)+2(1)
mm= 18.0g/mol. n=34.53mol
hence, m=34.53mol*18.0g/mol
m=621.54g