1. A stock phenolphthalein solution was prepared by dissolving 0.050 g in a tota

Question

1. A stock phenolphthalein solution was prepared by dissolving 0.050 g in a total volume of 100.0 ml. You place one drop (0.050 ml) of this stock solution into a flask and dilute to 100.0 ml. The measured absorbance of this diluted sample is 0.18. What is the value of molar absorptivity, ??

225000 abs units

230000 M-1cm-1

229000 M-1cm-1

2.3 X 10-5 abs units

2. You record a time of 25 seconds for the absorbance to reduce from 0.96 to 0.48. What is the rate of reaction during this time. Use the constant determined in question one.

Question 2 options:

8.4 X 10-8 M/s

0.019 M/s

1.7 X 10-7 M/s

8.3 X 10-8 M/s

225000 abs units

Explanation / Answer

1. A stock phenolphthalein solution was prepared by dissolving 0.050 g in a total volume of 100.0 ml. You place one drop (0.050 ml) of this stock solution into a flask and dilute to 100.0 ml. The measured absorbance of this diluted sample is 0.18. What is the value of molar absorptivity, ??

Ans:D)2.3 X 10-5 abs units

2. You record a time of 25 seconds for the absorbance to reduce from 0.96 to 0.48. What is the rate of reaction during this time. Use the constant determined in question one.

Ans:

0.019 M/s

0.019 M/s

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

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