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.
Answer: 4.) CH3O is the answer, which stands for Methoxide.
Explanation:
Answer:
Answer: Energy from the sun.
Explanation:
<em>If you look at the hints it says that it needs something else for a plant to grow and what does a plant need? </em>
<em />
<em>Air, Water, and energy from the Sun to make food</em>
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<em>Hope this helps :)</em>
Answer: alkaline earth metals (group-IIA)
Explanation:
The element which donates the electron is known as electropositive element and forms a positively charged ion called as cation. The element which accepts the electrons is known as electronegative element and forms a negatively charged ion called as anion.
Alkaline earth metals donate 2 valence electrons to acquire noble gas configuration.
For example: Berrylium is the first alkaline earth metal with atomic number of 4 and thus has 4 electrons
Electronic configuration of berrylium:
![[Be]:4:1s^22s^2](https://tex.z-dn.net/?f=%5BBe%5D%3A4%3A1s%5E22s%5E2)
Berrylium atom will loose two electrons to gain noble gas configuration and form berrylium cation with +2 charge.
![[Be^{2+}]:2:1s^2](https://tex.z-dn.net/?f=%5BBe%5E%7B2%2B%7D%5D%3A2%3A1s%5E2)
Thus Elements donate 2 electron to produce a cation with a 2+ charge are alkaline earth metals.
Hey there!
Consider 100 g of solution:
Mass of NaCl = 3.50% of mass of seawater
( 3.50 / 100 ) * 100 => 3.50 g
Number of moles as shown below:
Molar mass NaCl = 58.44 g/mol
n = Mass / molar mass
n = 3.50 / 58.44 => 0.059 moles of NaCl
Mass of sweater:
Mass of solution - Mass of NaCl
100 - 3.50 = 96.5 g
96.5 g in Kg :
96.5 / 1000 => 0.0965 Kg
Therefore ,calculate molality by using the following formula:
molality = number of moles of solute / mass of solution
molality = 0.059 / 0.0965
molality = 0.61 m
Hope That helps!
