Answer:
The hydroxide ions decrease.
Explanation:
I got it right on the quiz. This is what I saw. Read this, "Adding water to an acid or base will change its pH. Water is mostly water molecules so adding water to an acid or base reduces the concentration of ions in the solution. When an acidic solution is diluted with water the concentration of H + ions decreases and the pH of the solution increases towards 7."
Hope this helps! Tell me if this is wrong just incase.
Answer:

Explanation:
C = Allowable concentration = 1.1 mg/L
= Flow rate of river = 
= Discharge from plant = 
= Background concentration = 0.69 mg/L
= Maximum concentration that of the pollutant
The concentration of the mixture will be

The maximum concentration that of the pollutant (in mg/L) that can be safely discharged from the wastewater treatment plant is
.
The answer to this question I think would be 2: Better
Answer:
For 12.8 g there 0.807 × 10³ formula units.
Explanation:
Given data:
Mass of MgCl₂ = 12.8 g
Formula units for given mass = ?
Solution:
First of all we will calculate the number of moles.
Number of moles = mass/molar masss
Number of moles = 12.8 g/ 95.211 g/mol
Number of moles = 0.134 mol
According to the Avogadro number,
one moles = 6.022 × 10³ formula units
For 0.134 mol,
0.134 × 6.022 × 10³ formula units
0.807 × 10³ formula units
For 12.8 g there 0.807 × 10³ formula units.