Answer:
It is mentioned that the student is mixing chemicals A and B and observes the time taken for the color to change. However, in the experiment, it is noticed that the student has repeated the procedure five times and each time he or she is modifying the concentration of chemical B. Thus, it is clear that the concentration of chemical B is the independent variable in the experiment. An independent variable is illustrated as the variable, which is controlled or modified in the experiment.
Answer:
1) 0.18106 M is the molarity of the resulting solution.
2) 0.823 Molar is the molarity of the solution.
Explanation:
1) Volume of stock solution = 
Concentration of stock solution = 
Volume of stock solution after dilution = 
Concentration of stock solution after dilution = 
( dilution )

0.18106 M is the molarity of the resulting solution.
2)
Molarity of the solution is the moles of compound in 1 Liter solutions.

Mass of potassium permanganate = 13.0 g
Molar mass of potassium permangante = 158 g/mol
Volume of the solution = 100.00 mL = 0.100 L ( 1 mL=0.001 L)

0.823 Molar is the molarity of the solution.
So a camera can zoom in and out and the human eye has peripheral vision
<span>0.0200 L X 0.06 mol/L HCl = 1.2X10^-3 mol HCl
Moles NaOH added to reach equivalence point = 1.2X10^-3 mol NaOH
Volume NaOH = 1.2X10^-3 mol / 0.0400 M NaOH = 0.030 L NaOH = 30 mL NaOH
</span>
D.There is a rapid change in pH near the equivalence point (pH = 7)
hope it helps