Answer : The
ion concentration is,
and the pH of a buffer is, 2.95
Explanation : Given,

Concentration of
(weak acid)= 0.26 M
Concentration of
(conjugate base or salt)= 0.89 M
First we have to calculate the value of
.
The expression used for the calculation of
is,

Now put the value of
in this expression, we get:



Now we have to calculate the pH of the solution.
Using Henderson Hesselbach equation :
![pH=pK_a+\log \frac{[Salt]}{[Acid]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BSalt%5D%7D%7B%5BAcid%5D%7D)
![pH=pK_a+\log \frac{[KNO_2]}{[HNO_2]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BKNO_2%5D%7D%7B%5BHNO_2%5D%7D)
Now put all the given values in this expression, we get:


The pH of a buffer is, 2.95
Now we have to calculate the
ion concentration.
![pH=-\log [H_3O^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH_3O%5E%2B%5D)
![2.95=-\log [H_3O^+]](https://tex.z-dn.net/?f=2.95%3D-%5Clog%20%5BH_3O%5E%2B%5D)
![[H_3O^+]=1.12\times 10^{-3}M](https://tex.z-dn.net/?f=%5BH_3O%5E%2B%5D%3D1.12%5Ctimes%2010%5E%7B-3%7DM)
The
ion concentration is, 
Molar mass of C: 12.011 g/mol
The equation says C20, which means there are 20 carbon atoms in each molecule of Vitamin A. So, we multiply 12.011 by 20 to get 240.22 g/mol carbon.
Molar mass of H: 1.0079 g/mol
The equation says C30, which means there are 30 hydrogen atoms in each molecule of Vitamin A. So, we multiply 1.0079 by 30 to get 30.237 g/mol hydrogen.
Molar mass of O: 15.999 g/mol
The equation says O without a number, which means there is only one oxygen atom in each molecule of Vitamin A. So, we leave O at 15.999 g/mol.
Then, just add it up:
240.22 g/mol C + 30.237 g/mol H + 15.999 g/mol O = 286.456 g/mol C20H30O
So, the molar mass of Vitamin A, C20H30O, is approximately 286.5 g/mol.
The answer is D, species!
Hope this helps!
Answer:
Covalent bonds.
Explanation:
Diamond is organized in a giant lattice structure with strong covalent bonds between carbon atoms. Each carbon atom forms 4 bonds. Explanation: Each carbon atom has four electrons in its outer shell, all of which form covalent bonds that are strong and hard to break.