<span>[H3O+] = 10^(-pH) = 10^(-4.20) = 6.3 x 10^-5 M
pOH = 14 - pH = 14 - 4.20 = 9.80
[OH-] = 10^(-pOH) = 10^(-9.80) = 1.6 x 10^-10 M
</span>
Explanation:
2.658x 10 to the 23 power
The question is incomplete, complete question is :
Determine the pH of an HF solution of each of the following concentrations. In which cases can you not make the simplifying assumption that x is small? (
for HF is
.)
[HF] = 0.280 M
Express your answer to two decimal places.
Answer:
The pH of an 0.280 M HF solution is 1.87.
Explanation:3
Initial concentration if HF = c = 0.280 M
Dissociation constant of the HF = 

Initially
c 0 0
At equilibrium :
(c-x) x x
The expression of disassociation constant is given as:
![K_a=\frac{[H^+][F^-]}{[HF]}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%5BH%5E%2B%5D%5BF%5E-%5D%7D%7B%5BHF%5D%7D)


Solving for x, we get:
x = 0.01346 M
So, the concentration of hydrogen ion at equilibrium is :
![[H^+]=x=0.01346 M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3Dx%3D0.01346%20M)
The pH of the solution is ;
![pH=-\log[H^+]=-\log[0.01346 M]=1.87](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BH%5E%2B%5D%3D-%5Clog%5B0.01346%20M%5D%3D1.87)
The pH of an 0.280 M HF solution is 1.87.
Filter flasks are
also known as vacuum, suction or the Buchner flasks. They have thick walls and also
have a short glass tube. The thick walls are designed to enable the filter withstand
high pressures of vacuum applied to filter substances. Generally this is used
for filtering.
While the Erlenmeyer flask
also called as a conical flask, is a titration flask which consists of a
conical body, a flat bottom, and round neck. This is used for used for general
uses such as mixing, titrations, preparation of cultures, for
recrystallization, and for supporting filter funnels.
<span>Lastly, the Volumetric flasks are graduated flasks which having markings
for different volumes. They are calibrated accurately for a specific amount of
liquid that can be contained in it hence this is specially used for storing
precise amounts of liquid. </span>
Answer:
C. Lose three electrons to have a full outer shell
Explanation:
Al is in Group 13 of the Periodic Table, so it has three valence electrons.
It must either lose three electrons or gain five to achieve a stable octet.
It is easier to lose three electrons than it is to gain five, so Al loses three electrons.
D. is wrong, for the same reason.
A. is wrong. If Al lost three electrons, it would be breaking into a stable inner shell.
C. is wrong. Al is a metal, so it will lose electrons in a reaction.