To draw the Lewis structure of the polyatomic ion, 
you would have to add one electron to those in the structures of Cl, O, O and O.
Answer: Option A
<u>Explanation:</u>
It is a kind of representation of electrons present in valence shell of each element. For easy understanding of how the outermost electrons will be arranged for bonding purpose, Lewis structure is used.
As we know that carbon has an outermost electron number of 4. So 4 electrons are required as the electrons in the outermost shell of each carbon. But here only three electrons are there, so one electron need to be added in the Lewis structure of .
<span>This theory was first proposed by Nicolaus Copernicus. hope it helps</span>
Answer:
90 g CH₃NH₃Cl
Explanation:
It appears your question lacks the values required to solve this problem. However, an online search tells me these are the values. Be aware if your values are different your answer will also be different, but the methodology remains the same.
" A chemistry graduate student is given 450 mL of a 1.70 M methylamine solution. Methylamine is a weak base with Kb=4.4x10⁻⁴. What mass of CH₃NH₃Cl should the student dissolve in the methylamine solution to turn it into a buffer with pH = 10.40 ? You may assume that the volume of the solution doesn't change when the is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits. "
We'll use the <u>Henderson-Hasselbach equation</u>:
- pH = pKa + log
![\frac{[Methylamine]}{[Salt]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BMethylamine%5D%7D%7B%5BSalt%5D%7D)
So first we <u>use Kb to calculate Ka and then pKa</u>:
- Ka = Kw/Kb ⇒ Ka = 1x10⁻¹⁴/4.4x10⁻⁴ = 2.27x10⁻¹¹
Now we can <u>calculate the concentration of the salt</u>, CH₃NH₃Cl:
- pH = pKa + log
- 10.40 = 10.64 + log
![\frac{1.70}{[Salt]}](https://tex.z-dn.net/?f=%5Cfrac%7B1.70%7D%7B%5BSalt%5D%7D)
- -0.24 = log
=
Now we use the final volume to <u>calculate the moles of CH₃NH₃Cl and finally its mass</u>, using its molecular weight:
- 450 mL ⇒ 450/1000 = 0.450 L
- 2.95 M * 0.450 L = 1.3275 mol CH₃NH₃Cl
- 1.3275 mol CH₃NH₃Cl * 67.45 g/mol = 89.54 g CH₃NH₃Cl
Which when rounded to 2 significant digits becomes 90 g CH₃NH₃Cl
Ten protons would be Neon, but the most stable? I'd have to say 12 neutrons in contrast to the 10 protons. Not too negative in balance.
