Answer:
Concentration: 0.185M HX
Ka = 9.836x10⁻⁶
pKa = 5.01
Explanation:
A weak acid, HX, reacts with NaOH as follows:
HX + NaOH → NaX + H2O
<em>Where 1 mole of HX reacts with 1 mole of NaOH</em>
To solve this question we need to find the moles of NaOH at equivalence point (Were moles HX = Moles NaOH).
18.50mL = 0.01850L * (0.20mol / L) = 0.00370 moles NaOH = Moles HX
In 20.0mL = 0.0200L =
0.00370 moles HX / 0.0200L = 0.185M HX
The equilibrium of HX is:
HX(aq) ⇄ H⁺(aq) + X⁻(aq)
And Ka is defined as:
Ka = [H⁺] [X⁻] / [HX]
<em>Where [H⁺] = [X⁻] because comes from the same equilibrium</em>
As pH = 2.87, [H+] = 10^-pH = 1.349x10⁻³M
Replacing:
Ka = [H⁺] [H⁺] / [HX]
Ka = [1.349x10⁻³M]² / [0.185M]
Ka = 9.836x10⁻⁶
pKa = -log Ka
<h3>pKa = 5.01</h3>
Answer:
coastal and sea floor features influence their location direction and speed coriolis effect also influence deep ocean current
Based on atomic mass
Explanation:
Elements were arranged on the first periodic table based on their atomic masses.
The mass of an atom is made up of the mass of the nucleus which contains the protons and neutrons.
- Dimitri Mendeleev was the first person credited for arranging elements periodically.
- He was said to have been inspired while playing his game of solitaire on a train.
- On his table, he left spaces for the atomic masses of elements not yet discovered.
- Today, the periodic table is based on the atomic numbers of elements. This is the number of protons in an atom.
Learn more:
Periodic table brainly.com/question/2690837
#learnwithBrainly
Those would be called indicators , simply google them and you should find many. I'll leave some examples "bromophenol blue" "Methyl red" and "phenol red".
