Question 1

A Beer-Lambert analysis showed the extinction coefficient for compound B in water to be 345 m2 mol−1 at 450 nm. A different solution of compound B is analysed by UV/visible spectroscopy and the absorbance at 450 nm is recorded as 0.28 in a 1.00 cm cell. What is the concentration of this solution?

Accepted Answer

A)   8.1 × 10−4 mol dm-3
B)   1.2 mmol dm-3
C)   12 mol dm-3
D)   8.1 mol dm-3E) C) and D)
F) None of the above

Question 2

The limit for the detection of Cl- ions in a sample of mineral water through gravimetric analysis is quoted as 2.5 ppb by mass. Express this detection limit as a molar concentration of Cl- ions, given that the density of water is 1.00 g cm-3.

Accepted Answer

A)   2.5  10-9 mol cm-3
B)   7.1  10-11 mol cm-3
C)   1.3  10-9 mol cm-3
D)   3.6  10-11 mol cm-3E) B) and D)
F) None of the above

Question 3

Propane has a retention time of 4.1 minutes and ethane has a retention time of 2.1 minutes in a particular gas chromatogram. Determine the relative retention of propane to ethane.

Accepted Answer

A)   1.95
B)   0.51
C)   4.10
D)   0.24E) All of the above
F) A) and B)

Question 4

Determine the relative retention time for the two enantiomers shown in Box 11.5

Accepted Answer

A)   0.60
B)   4.80
C)   1.66
D)   2.89E) C) and D)
F) B) and C)

Exam 11: Analytical Chemistry

Determine the relative retention time for the two enantiomers shown in Box 11.5

Correct Answer
verified

The limit for the detection of Cl^- ions in a sample of mineral water through gravimetric analysis is quoted as 2.5 ppb by mass. Express this detection limit as a molar concentration of Cl^- ions, given that the density of water is 1.00 g cm^-3.

Correct Answer
verified

Propane has a retention time of 4.1 minutes and ethane has a retention time of 2.1 minutes in a particular gas chromatogram. Determine the relative retention of propane to ethane.

Correct Answer
verified

Correct Answer
verified

Exam 11: Analytical Chemistry

Determine the relative retention time for the two enantiomers shown in Box 11.5

Correct AnswerverifiedShow Answer

The limit for the detection of Cl- ions in a sample of mineral water through gravimetric analysis is quoted as 2.5 ppb by mass. Express this detection limit as a molar concentration of Cl- ions, given that the density of water is 1.00 g cm-3.

Correct AnswerverifiedShow Answer

Propane has a retention time of 4.1 minutes and ethane has a retention time of 2.1 minutes in a particular gas chromatogram. Determine the relative retention of propane to ethane.

Correct AnswerverifiedShow Answer

A Beer-Lambert analysis showed the extinction coefficient for compound B in water to be 345 m2 mol−1 at 450 nm. A different solution of compound B is analysed by UV/visible spectroscopy and the absorbance at 450 nm is recorded as 0.28 in a 1.00 cm cell. What is the concentration of this solution?

Correct AnswerverifiedShow Answer

Correct Answer
verified

The limit for the detection of Cl^- ions in a sample of mineral water through gravimetric analysis is quoted as 2.5 ppb by mass. Express this detection limit as a molar concentration of Cl^- ions, given that the density of water is 1.00 g cm^-3.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified