<span>3.75 gallons need to be drained and replaced with bleach.
Change the problem to "What amounts of a 100% solution and a 4% solution is needed to make 90 gallons of a 8% solution?" Given that, we'll use the following values.
x = amount of 4% solution.
90-x = amount of a 100% solution.
The equation to solve then becomes.
0.04 x + (90-x) = 0.08 * 90
0.04 x + 90 - x = 7.2
Add x to both sides
0.04x + 90 = 7.2 + x
Subtract 0.04x from both sides
90 = 7.2 + 0.96x
Subtract 7.2 from both sides
82.8 = 0.96x
Divide both sides by 0.96
86.25 = x
So you now know that you need 86.25 gallons of the original 4% solution and (90-86.25) = 3.75 gallons of the bleach to make the desired 90 gallons.
So simply drain 3.75 gallons from the tank and replace with bleach.</span>
Answer:
counting the number of “groups” of electrons around the atom
Explanation:
=>
Answer:
0.4
Explanation:
Given parameters:
Mass of NaCl = 0.564g
Mass of KCl = 1.52g
Mass of LiCl = 0.857g
Unknown:
Mole fraction of KCl = ?
Solution:
First, find the number of moles of the given species;
Number of moles =
Molar mass of KCl = 39 + 35.5 = 74.5g/mol
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Molar mass of LiCl = 7 + 35.5 = 42.5g/mol
Number of moles of KCl = = 0.02mol
Number of moles of NaCl = = 0.0096mol
Number of moles of LiCl = = 0.02mol
Sum of moles = 0.02mol + 0.0096mol + 0.02mol = 0.0496mol
Mole fraction of KCl = = 0.4
The answer is gully, <span> a large channel in soil that carries runoff after a rainstorm</span>