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:
They are pollinators of alfalfa.
Explanation:
Without them crops wouldn't be here.
Because the reactants react with each other and chemically react to produce a different product like with fire when it reacts with the wood it burns and the product left behind is a new different substance from the reactants in this case the product is ash
The amount of oxygen that are produced when 1.06 grams of potassium chlorate decompose completely is 0.64 grams.
<h3>What is the relation between mass & moles?</h3>
Relation between the mass and moles of any substance will be represented as:
- n = W/M, where
- W = given mass
- M = molar mass
Moles of potassium chlorate = 1.66g / 122.5g/mol = 0.0135mole
Given chemical reaction is:
2KClO₃ → 2KCl + 3O₂
From the stoichiometry of the reaction, it is clear that:
2 moles of KClO₃ = produces 3 moles of O₂
0.0135 moles of KClO₃ = produces (3/2)(0.0135)=0.02 moles of O₂
Mass of oxygen = (0.02mol)(32g/mol) = 0.64 g
Hence produced mass of oxygen is 0.64 grams.
To now more about mass & moles, visit the below link:
brainly.com/question/18983376
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Answer: A strong acid like HCl dissociates completely in an aqueous solution.
By definition a strong acid is that that dissociates completely in aqueous solutions. That means that all the molecules of the acid will be inoized into hydronium cation (H3O+) and anion (the negative radical).
For expample, HCl is a strong acid because
HCl + H2O----> H3O(+) + Cl-
The forwar arrow indicates that all the molecules of HCl reacted with the water for form the ions.
