Answer: The pH of 0.10 M
is 4.49.
Explanation:
Given: Initial concentration of
= 0.10 M

Let us assume that amount of
dissociates is x. So, ICE table for dissociation of
is as follows.
![Cu(H_{2}O)^{2+}_{6} \rightleftharpoons [Cu(H_{2}O)_{5}(OH)]^{+} + H_{3}O^{+}](https://tex.z-dn.net/?f=Cu%28H_%7B2%7DO%29%5E%7B2%2B%7D_%7B6%7D%20%5Crightleftharpoons%20%5BCu%28H_%7B2%7DO%29_%7B5%7D%28OH%29%5D%5E%7B%2B%7D%20%2B%20H_%7B3%7DO%5E%7B%2B%7D)
Initial: 0.10 M 0 0
Change: -x +x +x
Equilibrium: (0.10 - x) M x x
As the value of
is very small. So, it is assumed that the compound will dissociate very less. Hence, x << 0.10 M.
And, (0.10 - x) will be approximately equal to 0.10 M.
The expression for
value is as follows.
![K_{a} = \frac{[Cu(H_{2}O)^{2+}_{6}][H_{3}O^{+}]}{[Cu(H_{2}O)^{2+}_{6}]}\\1.0 \times 10^{-8} = \frac{x \times x}{0.10}\\x = 3.2 \times 10^{-5}](https://tex.z-dn.net/?f=K_%7Ba%7D%20%3D%20%5Cfrac%7B%5BCu%28H_%7B2%7DO%29%5E%7B2%2B%7D_%7B6%7D%5D%5BH_%7B3%7DO%5E%7B%2B%7D%5D%7D%7B%5BCu%28H_%7B2%7DO%29%5E%7B2%2B%7D_%7B6%7D%5D%7D%5C%5C1.0%20%5Ctimes%2010%5E%7B-8%7D%20%3D%20%5Cfrac%7Bx%20%5Ctimes%20x%7D%7B0.10%7D%5C%5Cx%20%3D%203.2%20%5Ctimes%2010%5E%7B-5%7D)
Hence, ![[H_{3}O^{+}] = 3.2 \times 10^{-5}](https://tex.z-dn.net/?f=%5BH_%7B3%7DO%5E%7B%2B%7D%5D%20%3D%203.2%20%5Ctimes%2010%5E%7B-5%7D)
Formula to calculate pH is as follows.
![pH = -log [H^{+}]](https://tex.z-dn.net/?f=pH%20%3D%20-log%20%5BH%5E%7B%2B%7D%5D)
Substitute the values into above formula as follows.
![pH = -log [H^{+}]\\= - log (3.2 \times 10^{-5})\\= 4.49](https://tex.z-dn.net/?f=pH%20%3D%20-log%20%5BH%5E%7B%2B%7D%5D%5C%5C%3D%20-%20log%20%283.2%20%5Ctimes%2010%5E%7B-5%7D%29%5C%5C%3D%204.49)
Thus, we can conclude that the pH of 0.10 M
is 4.49.
Answer:
2,981g
Explanation:
Firstly, we need to find the number of moles of MgCl that we have by using the formula: mass = No. Moles x Molar Mass, which we can rearrange so that we are solving for no. moles:
No. Moles = mass / Molar Mass
We are given a mass of 621g, and we can calculate the molar mass of MgCl by adding the two molar masses together: 24.31+35.45 = 59.76
Now we can calculate number of moles by substituting these values into the formula:
n = 621 / 59.76
No. moles = 10.4
Now we can use the co-efficients in the formula to tell us how many moles of AgCl will be formed. The coefficient of MgCl is 1, and the coefficient of AgCl is 2. This means that every 1 mol of MgCl will form 2 moles of AgCl. So, to find the no. moles of AgCl, we multiply our no. moles by 2:
10.4 x 2 = 20.8 moles
Finally we convert this back into mass by multiplying the no. moles by the Molar mass of AgCl:
m = 20.8 x (107.87+35.45)
m = 2,981g
Answer:
<u>O-H stretch signal at 3300 cm-1</u>
Explanation:
In this question, we can start with the <u>reaction mechanism</u> for the synthesis of Nerolin. We have to start with naphthalen-2-ol adding NaOH we can produce the alkoxide. Then this alkoxide can react by an <u>Sn2 reaction</u> with bromomethane to produce Nerolin (see figure 1).
In the starting molecule (naphthalen-2-ol) we have an <u>"OH" group</u>. Therefore we will have an <u>O-H stretch signal</u> around 3300 cm^-1. The alcohol signals are very broad and very intense, so this will be the main signal for the initial molecule. In the final product, we dont have the "OH" therefore this signal will disappear (see figure 2).
I hope it helps!
In order to knw hw stable an atom is