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.
When 2 elements are combined it creates an ionic compound
Answer:
Weak bonds require less energy to form than strong bonds
Explanation:
According to Coulomb's law, the force between two species is inversely proportional to the distance between them. That said, the bigger the atoms are, the greater the bond length should be to form a molecule.
As a result, for a greater bond length, the attraction force is lower than for a shorter bond length. This implies that large atoms would form weak bonds and small atoms would form strong bonds.
Bond energy is defined as the amount of energy required to break the bond. If a bond is weak, it would require a low amount of energy to break it. This is also true for energy of formation, as it's the same process taking place in the opposite direction.
A rock is a solid, so Logan can't poke his finger through it.
Answer:
2000pound
Explanation:
Manganese metal is produced from the manganese(III) oxide, Mn2O3, which is found in manganite, a manganese ore. The manganese is reduced from its +3 oxidation state in Mn2O3 to the zero oxidation state of the uncharged metal by reacting the Mn2O3 with a reducing agent such as aluminum or carbon. How many pounds of manganese are in 1.261 tons of Mn2O3? (1 ton = 2000 pounds)
About 40 different substances called organophosphorus compounds are registered in the United States as insecticides. They are considered less damaging to the environment than some other insecticides because they breakdown relatively rapidly in the environment. The first of these organophosphorus insecticides to be produced was tetraethyl pyrophosphate, TEPP, which is 33.11% carbon, 6.95% hydrogen, 38.59% oxygen, and 21.35% phosphorus. It has a molecular mass of 290.190.
