1) Chemical reaction: HCN + H₂O → CN⁻ + H₃O⁺.
c(HCN) = 2,2 M = 2,2 mol/L.
pKa(HCN) = 9,21.
Ka = 6,16·10⁻¹⁰.
[CN⁻] = [H₃O⁺] = x.
[HCN<span>] = 2,2 M - x.
</span>Ka = [CN⁻] · [H₃O⁺] / [HCN].
6,16·10⁻¹⁰ = x² / 2,2 M -x.
Solve quadratic equation: [CN⁻] = [H₃O⁺] = 0,0000346 M.
[HCN] = 2,2 M - 0,0000346 M = 2,199 M.
2) pH = - log[H₃O⁺].
pH = -log( 0,0000346 M).
pH = 4,46.
Hydrocyanic acid and hydronium ion (H₃O⁺) are acids. Cyanide anion (CN⁻) is the strongest base in the system, cyanide anion accept protons in chemical reaction.
pKb = pKw - pKa.
pKb = 14 - 9,21 = 4,79.
The answer to this question would be: <span>B. They have a higher mass
The mass of an atom is determined by their mass number which was the sum of their protons and neutrons. Protons of an element will be same. So any isotope of an element will have the same number of proton, no isotope should have more proton. The mass is increased because some isotope has more neutrons than others, resulting in a higher mass.</span>
If the pH of the acid at a given time is found to be 1.25, then the molarity of the gastric acid juice is 0.056M.
<h3>What is pH?</h3>
pH is define as the negative logarithm of the concentration of H⁺ ions present in any solution and it will be represented as:
pH = -log[H⁺]
Concentration will be present in the form of molarity and pH value for gastric acid is given 1.25 means it is strong acid as it completely dissociates into their ions.
Required equation for calculation will be:
[H⁺] = ![10^{-pH}](https://tex.z-dn.net/?f=10%5E%7B-pH%7D)
[H⁺] = ![10^{-1.25}](https://tex.z-dn.net/?f=10%5E%7B-1.25%7D)
[H⁺] = 0.056 M
Hence molarity of the gastric acid juice is 0.056M.
To know more about pH & molarity, visit the below link:
brainly.com/question/27298208
Adding an atom affect the position of existing atoms and lone pairs by changing the geomertry and <span>changing postion of the lone pairs and atoms so that they are furthest apart. Hope this answers the question. Have a nice day.</span>