<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>
328.95 g/l because you multiply
Answer is: no, every sample does not have a negative charge.
Beside negatively charged electrons, atoms have positively charged protons, so atoms have neutral charge.
Atomic number is the number of protons, which is characteristic of a chemical element. For example, iron (Fe) is an element with atomic number 26, which means it has 26 protons and 26 electrons (in neutral atom, number of protons is equal to number of electrons).
The electron (symbol: e⁻) is a subatomic particle whose electric charge is negative one elementary charge.
Proton is a subatomic particle with a positive electric charge of +1e elementary charge.
Answer:
the option e is correct I think
The solution is either saturated or supersaturated with solute
H2O(s) ==> H2O(l)
<span>The density of liquid H2O = 1.00 g/mL. </span>
<span>The density of ice is 0.917 g/mL. </span>
<span>Suppose we start with 1 mol (18 g) H2O(s) and it melts to the liquid. </span>
<span>As a liquid it will occupy 18g/1.00 = 18 mL. </span>
<span>As a solid it will occupy 18/0.917 = 19.63 mL. </span>
<span>19.63-18.0 = 1.63 mL diffeence. </span>
<span>The heat fusion of ice is 6.01 kJ/mol; therefore, 6.01/1.63 = about 3.69 kJ for each mL difference. </span>
<span>In this experiment we have a difference of 0.109 mL; then 3.69 kJ/mL x 0.109 mL = 0.402 kJ for 0.0657 g Zn. You want per mol Zn and you have 0.0657/65.39 = about 0.001 mol Zn so </span>
0.402 kJ/0.001 = <span>402 kJ/mol Zn</span>