Chapter 3 Multiple Choice Questions

* not completed

. For a substance which absorbs light (in the visible region) with wavelength λ = 550 nm, the corresponding energy absorbed by 1 mole of material corresponds to which of the following?

90 kJ correct incorrect

200 J correct incorrect

196 kJ correct incorrect

315 kJ correct incorrect

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. For a molecule in solution for which the absorption A at λ _max is measured as 0.85 for a concentration of 0.3 mol m^-3 in a spectrometer cell of path length 1 cm, the molar decadic absorptivity (ɛ), in m² mol^-1, is which of the following?

0.3 correct incorrect

2.8 x 10² correct incorrect

2.8 correct incorrect

56 correct incorrect

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. The molecule β-carotene has λ_max 450 nm, and ɛ = 15,000 m² mol^-1. Calculate the absorption (A) expected for a solution in which 0.1 mg has been dissolved in 10 ml of water (given: the molecular weight of β-carotene, C₄₀H₅₆, as 536) with a path length of 1 cm.

2.8 correct incorrect

2.8 x 10^-4 correct incorrect

0.28 correct incorrect

0.028 correct incorrect

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. Which of the following ketones has the longest wavelength n→ π* absorption?

A correct incorrect

B correct incorrect

C correct incorrect

D correct incorrect