Answer:
The answer to your question is: 3.745 x 10 ²³ atoms
Explanation:
Data
density = 8.96 g/cm³
mass = 29.54 g
atomic radius = 1.28 A° 1.28 x 10⁻¹⁰ m
Volume of a cube
density = mass / volume
volume = mass / density
volume = 29.54 / 8.96
volume = 3.29 cm³
Volume of a copper atom
volume = (4/3) πr³
volume = (4/3) π (1.28 x 10 ⁻⁸)³
= 8.784 x 10 ⁻²⁴ cm³
Number of atoms = 3.29 cm³ / 8.784 x 10 ⁻²⁴ cm³
= 3.745 x 10 ²³ atoms
Okay I need an explanation from YOU. when is this due? If it’s last minute, why didn’t you do it when you had time? This is very irresponsible, unless you have a personal reason. Please quit commenting on others just for the points. I helped you with one, because I thought it was just one question you needed help with. No one is going to finish this for you. I’m sorry but it’s the truth, everyone here needs help. No one is here TO help. So please be cooperative and try to learn. Of course, I’m sorry if it is for a very personal reason as it happens to everyone where you need the work ASAP because of a reason. Hopefully, it’s not because you were lazy. Appreciate your education as not many people in the world have it.
I am pretty sure the correct answer is B.
It makes the most sense to me.
Answer:

Explanation:
pH is derived from the concentration of hydronium ions in a solution. Hydrocyanic acid is HCN.
First, we shall figure out the moles of HCN:

If HCN was a strong acid:
HCN has a 1:1 ratio of H+ ions, the moles of H+ is also the same.
To find the molarity, we now divide by Liters. This gets us:

Finally, we plug it into the definition of pH:
![pH = -log[H^{+} ]](https://tex.z-dn.net/?f=pH%20%3D%20-log%5BH%5E%7B%2B%7D%20%5D)


However, since HCN is a weak acid, it only partially dissociates. The
of HCN is
.
![K_a = \frac{[H^+][A^-]}{[HA]}](https://tex.z-dn.net/?f=K_a%20%3D%20%5Cfrac%7B%5BH%5E%2B%5D%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
We can use an ice table to determine that when x = H+,

![[H^+] = 8.83*10^{-6}](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%20%3D%208.83%2A10%5E%7B-6%7D)
![pH = -log[H^{+} ]](https://tex.z-dn.net/?f=pH%20%3D%20-log%5BH%5E%7B%2B%7D%20%5D)

