Consider the following dilution steps from a 3.51 M stock solution of H2SO4. 25
ID: 909791 • Letter: C
Question
Consider the following dilution steps from a 3.51 M stock solution of H2SO4.
25 mL of the 3.51 M stock solution 1 is diluted to 150 mL to make solution 2.
35 mL of solution 2 is diluted to 200 mL to make solution 3.
45 mL of solution 3 is diluted to 250 mL to make solution 4.
50 mL of solution 4 is diluted to 300 mL to make solution 5.
Calculate the concentration, in M, for solution 5.
Derive a single equation to calculate the concentration of solution 5 using only the molatiry of the stock solution and the various volumes.
Explanation / Answer
Answer:
stock solution 1: 25 ml of 3.51 M H2SO4.
Ci = 3.51M
V1 = 25 ml
Millimoles of H2SO4 = Ci*V1
stock solution 2: 25 mL of the 3.51 M stock solution 1 is diluted to 150 mL to make solution 2.
Volume of solution, V2 = 150 ml
Molarity of solution = Ci*V1/V2
Volume of stock solution taken, V3 = 35 ml
Millimoles of H2SO4 in 35 ml o stock solution = Ci*V1/V2*V3
stock solution 3: 35 mL of solution 2 is diluted to 200 mL to make solution 3.
Volume of solution, V4 = 200 ml
Molarity of solution = Ci*V1/V2*V3/V4
Volume of stock solution taken, V5 =45 ml .
Millimoles of H2SO4 = Ci*V1/V2*V3/V4*V5
stock solution 4: 45 mL of solution 2 is diluted to 250 mL to make solution 4
Volume of solution, V6 = 250 ml
Molarity of solution = Ci*V1/V2*V3/V4*V5/V6
Volume of stock solution taken, V7 = 50 ml .
Millimoles of H2SO4 = Ci*V1/V2*V3/V4*V5/V6*V7
stock solution 5: 50 mL of solution 4 is diluted to 300 mL to make solution 5.
Volume of solution, V8 = 300 ml
Molarity of solution = Ci*(V1/V2)*(V3/V4)*(V5/V6)*(V7/V8)
Molarity of solution = 3.51*(25/150)*(35/200)*(45/250)*(50/300) = 0.00307125 M