Calculate the new concentrations of a set of 3 standards using 3 mL, 6mL, and 9m

Question

Calculate the new concentrations of a set of 3 standards using 3 mL, 6mL, and 9mL stock solution respectively, cach diluted to 10 mL of solution. The stock solution has a concentration of 0.3 M. Show all calculations. 2. What kind of graph would you expect from data of concentration in molarity and absorbance? 3. Calculate the concentration of a sample of unknown concentration for the following information: die concentration and absorbance was collected for 5 samples, the information is graphed and an equation of y=6.44x + 0.002 was obtained for the data. An unknown sample was analysis and found to have an absorbance of 0.778, what is the concentration of this sample?

Explanation / Answer

1) when 3 ml stock solution

M1 = 0.3 M , V1 = 3 mL

M2 = ? M , V2 = 10 mL

from

M1 V1 = M2 V2

0.3 x 3 = M2 x 10

M2 = 0.09 M

new concentration = 0.09 M

when 6 mL stock solution :

M1 V1 = M2 V2

0.3 x 6 = M2 x 10

M2 = 0.18 M

new concentration = 0.18 M

when 9 mL stock solution :

M1 V1 = M2 V2

0.3 x 9 = M2 x 10

M2 = 0.27 M

new concentration = 0.27 M

2)

the expected graph is linear graph

y = mx + C

where y = absorbance

x = concentration .

3)

y = 6.44x + 0.002

y = mx + C

where y = absorbance = 0.778

x = concentration .

y = 6.44x + 0.002

0.778 = 6.44x + 0.002

x = 0.1205

concentration = 0.1205 M

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.