You are given 350 mL a stock solution of 1.66E-02 M benzoic acid, MW = 122.125 g/mol.
Answer the following questions.
A. What is the number of moles present in the original stock solution?
B. You need to dilute the benzoic acid stock solution to 1.24E-03 M. If you need 455 mL of solution,
what volume of the original stock solution do you need to dilute?
C. What is the number of moles present in the new diluted solution?
D. You mass the solution to be 462.131 g. What is the density of the solution?
E. If the actual density should be 1.05 g/mL. What is your percent error?
Answered below.
A. To find the number of moles present in the original stock solution, you can use the formula:
moles = concentration (M) x volume (L)
Given:
Concentration of the solution (C) = 1.66E-02 M
Volume of the solution (V) = 350 mL
First, convert the volume from mL to L:
Volume (V) = 350 mL ÷ 1000 = 0.35 L
Substitute the values into the formula:
moles = 1.66E-02 M x 0.35 L
Now you can calculate the number of moles in the original stock solution.
B. To dilute the benzoic acid stock solution to a desired concentration, you can use the formula:
C1V1 = C2V2
Given:
Initial concentration (C1) = 1.66E-02 M
Desired concentration (C2) = 1.24E-03 M
Desired volume (V2) = 455 mL
First, convert the desired volume from mL to L:
Desired volume (V2) = 455 mL ÷ 1000 = 0.455 L
Now rearrange the formula to solve for the initial volume (V1):
V1 = (C2V2) / C1
Substitute the values into the formula to find the volume of the original stock solution needed to dilute:
V1 = (1.24E-03 M) x (0.455 L) / (1.66E-02 M)
C. To find the number of moles present in the new diluted solution, you can use the formula mentioned in part A:
moles = concentration (M) x volume (L)
Given:
Concentration of the new diluted solution (C) = 1.24E-03 M
Volume of the new diluted solution (V) = 455 mL
First, convert the volume from mL to L:
Volume (V) = 455 mL ÷ 1000 = 0.455 L
Substitute the values into the formula:
moles = 1.24E-03 M x 0.455 L
Now you can calculate the number of moles in the new diluted solution.
D. To find the density of the solution, you can use the formula:
density = mass / volume
Given:
Mass of the solution = 462.131 g
Volume of the solution = ?
Given the mass and assuming the volume is the same as before (455 mL), convert the volume from mL to L:
Volume = 455 mL ÷ 1000 = 0.455 L
Substitute the values into the formula:
density = 462.131 g / 0.455 L
Now you can calculate the density of the solution.
E. To calculate the percent error, you can use the formula:
percent error = |(actual value - experimental value)| / |actual value| x 100
Given:
Actual density = 1.05 g/mL
Experimental density = calculated density from part D
Substitute the values into the formula and calculate the percent error.