I believe the answer is C !
Answer:
Explanation:
Given parameters;
pH = 8.74
pH = 11.38
pH = 2.81
Unknown:
concentration of hydrogen ion and hydroxyl ion for each solution = ?
Solution
The pH of any solution is a convenient scale for measuring the hydrogen ion concentration of any solution.
It is graduated from 1 to 14
pH = -log[H₃O⁺]
pOH = -log[OH⁻]
pH + pOH = 14
Now let us solve;
pH = 8.74
since pH = -log[H₃O⁺]
8.74 = -log[H₃O⁺]
[H₃O⁺] = 10⁻![^{8.74}](https://tex.z-dn.net/?f=%5E%7B8.74%7D)
[H₃O⁺] = 1.82 x 10⁻⁹mol dm³
pH + pOH = 14
pOH = 14 - 8.74
pOH = 5.26
pOH = -log[OH⁻]
5.26 = -log[OH⁻]
[OH⁻] = 10![^{-5.26}](https://tex.z-dn.net/?f=%5E%7B-5.26%7D)
[OH⁻] = 5.5 x 10⁻⁶mol dm³
2. pH = 11.38
since pH = -log[H₃O⁺]
11.38 = -log[H₃O⁺]
[H₃O⁺] = 10⁻![^{11.38}](https://tex.z-dn.net/?f=%5E%7B11.38%7D)
[H₃O⁺] = 4.17 x 10⁻¹² mol dm³
pH + pOH = 14
pOH = 14 - 11.38
pOH = 2.62
pOH = -log[OH⁻]
2.62 = -log[OH⁻]
[OH⁻] = 10![^{-2.62}](https://tex.z-dn.net/?f=%5E%7B-2.62%7D)
[OH⁻] =2.4 x 10⁻³mol dm³
3. pH = 2.81
since pH = -log[H₃O⁺]
2.81 = -log[H₃O⁺]
[H₃O⁺] = 10⁻![^{2.81}](https://tex.z-dn.net/?f=%5E%7B2.81%7D)
[H₃O⁺] = 1.55 x 10⁻³ mol dm³
pH + pOH = 14
pOH = 14 - 2.81
pOH = 11.19
pOH = -log[OH⁻]
11.19 = -log[OH⁻]
[OH⁻] = 10![^{-11.19}](https://tex.z-dn.net/?f=%5E%7B-11.19%7D)
[OH⁻] =6.46 x 10⁻¹²mol dm³
(C) 0.1 mole of NaCl dissolved in 1,000. mL of water
<u>Explanation:</u>
The conductivity of 0.1 mole of NaCl dissolved in 1000 mL of water will be greatest as the number of ions in 0.1 mole of NaCl will be more than 0.001, 0.05 and 0.005 moles of NaCl. Greater the number of ions in the solution, greater will be the conductivity. Specific Conductivity decreases with a decrease in concentration. Since the number of ions per unit volume that carry current in a solution decrease on dilution. Hence, concentration and conductivity are directly proportional to each other.
Answer: The layers are ordered by density, with the least dense layer on top, and the densest layer on the bottom.
Explanation:
Plato
Electrons are emitted from the surface of a metal in photoelectric effect.
<h3>What is the photoelectric effect?</h3>
The photoelectric effect is the emission of electron from the surface of a metal when light is shone on the surface..
For electrons to be emitted, the light must have a certain frequency known as threshhold frequency.
Therefore, electrons are emitted from the surface of a metal in photoelectric effect.
Learn more about photoelectric effect at: brainly.com/question/21320305
#SPJ1