Answer: The volume of the new solution is 83.33 mL.
Explanation:
Given: 
= 200 mL, 
= 0.5 M
= ?, 
= 1.2 M
Formula used to calculate the volume of new solution is as follows.
Substitute the values into above formula as follows.
Thus, we can conclude that volume of the new solution is 83.33 mL.
When a solute is completely dissolved in a solvent, a solution is formed.
Answer:
So sorry if I was wrong but I think it's B. Because from the source states,
https://socratic.org/questions/which-group-on-the-periodic-table-is-the-least-reactive-why
"The least reactive elements are those who have a full outermost valence shell ie they have 8 electrons in the outer shell so elements such as helium, neon, radon or the transition elements."
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: A
The protons in the nucleus repel each other
Explanation:
the number of protons inside a nucleus increases the electrostatic repulsion between protons increase reducing the binding energy. Thus the electrostatic force determines the stability of a nuclear configuration
