D. F
Molecules are a group of bonded atoms but Fluorine stands on its own
The answer is A . Saturated solution
Answer:
a. 1.78x10⁻³ = Ka
2.75 = pKa
b. It is irrelevant.
Explanation:
a. The neutralization of a weak acid, HA, with a base can help to find Ka of the acid.
Equilibrium is:
HA ⇄ H⁺ + A⁻
And Ka is defined as:
Ka = [H⁺] [A⁻] / [HA]
The HA reacts with the base, XOH, thus:
HA + XOH → H₂O + A⁻ + X⁺
As you require 26.0mL of the base to consume all HA, if you add 13mL, the moles of HA will be the half of the initial moles and, the other half, will be A⁻
That means:
[HA] = [A⁻]
It is possible to obtain pKa from H-H equation (Equation used to find pH of a buffer), thus:
pH = pKa + log₁₀ [A⁻] / [HA]
Replacing:
2.75 = pKa + log₁₀ [A⁻] / [HA]
As [HA] = [A⁻]
2.75 = pKa + log₁₀ 1
<h3>2.75 = pKa</h3>
Knowing pKa = -log Ka
2.75 = -log Ka
10^-2.75 = Ka
<h3>1.78x10⁻³ = Ka</h3>
b. As you can see, the initial concentration of the acid was not necessary. The only thing you must know is that in the half of the titration, [HA] = [A⁻]. Thus, the initial concentration of the acid doesn't affect the initial calculation.
Atoms in the amino acids become the h₂O molecule produced by their action in the model and come off from the central carbon and nitrogen but not from the carboxyl, R side chain, or amine.
An amino acid is a group of organic molecules that consist of a basic acidic carboxyl group (―COOH), amino group (―NH2), and an organic R group (or side chain) that is different from each amino acid. Amino acid, the term is a short form of α-amino [alpha-amino] carboxylic acid.
Whereas, the peptide bond is the chemical bond which is a chemical bond formed between two molecules when the carboxyl group of a particular molecule reacts with the amino group of the other molecule, leading to releasing a molecule of water (H2O).
Each molecule consists of a central carbon atom referred to as the α-carbon, to which both a carboxyl group and amino are attached. The remaining two bonds of the α-carbon atom are generally occupied by the R group and a hydrogen (H) atom .
To know more about amino acids refer to the link brainly.com/question/14583479?referrer=searchResults.
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