Beer’s Law (or the Beer-Lambert Law) is . . .

a linear relationship between the intensity of a UV absorbance and the concentration of the analyte.

an inverse relationship between the IR stretching frequency and the energy of light.

used to derive a molecular formula from the mass-to-charge ratio of an analyte.

In UV absorption spectroscopy, which of the following statements are true?

A conjugated systems of double bonds in a molecular shifts the a absorption maxima to higher wavelengths

σ→σ* transitions are lower in energy than π→π* transitions

σ→σ* transitions are higher in energy than π→π* transitions

PA III (Pr) CA II

Reviewed by Editorial Team

The ProProfs editorial team is comprised of experienced subject matter experts. They've collectively created over 10,000 quizzes and lessons, serving over 100 million users. Our team includes in-house content moderators and subject matter experts, as well as a global network of rigorously trained contributors. All adhere to our comprehensive editorial guidelines, ensuring the delivery of high-quality content.

Learn about Our Editorial Process

| By Rajju

Rajju

Community Contributor

Quizzes Created: 3 | Total Attempts: 383

| Attempts: 114

Quiz Flashcard

Feedback

During the Quiz End of Quiz

Difficulty

Sequential Easy First Hard First

Share on Facebook Share on Twitter Share on Whatsapp Share on Pinterest Share on Email Copy to Clipboard Embed on your website

1/5 Questions

Beer’s Law (or the Beer-Lambert Law) is . . .
- A linear relationship between the intensity of a UV absorbance and the concentration of the analyte.
- An inverse relationship between the IR stretching frequency and the energy of light.
- An inverse relationship between the IR stretching frequency and the energy of light.
- Used to derive a molecular formula from the mass-to-charge ratio of an analyte.

About This Quiz

This quiz titled 'PA III (Pr) CA II' focuses on UV Spectroscopy, assessing understanding of Beer's Law, wavelength ranges, and compound characteristics related to UV\/visible light absorption. It's designed to enhance knowledge in analytical techniques critical for chemistry professionals.

2.

Which of the following wavelength ranges is associated with UV spectroscopy?
- 0.8 - 500µm
- 400 - 100nm
- 380 - 750nm
- 0.01 - 10nm
Correct Answer

A. 400 - 100nm

Explanation

UV spectroscopy is a technique that involves the measurement of the absorption or emission of ultraviolet (UV) light by molecules. The wavelength range associated with UV spectroscopy is typically between 400 and 100 nanometers (nm). This range is chosen because it corresponds to the energy levels of electrons in molecules, allowing for the study of electronic transitions. The other wavelength ranges listed in the options, such as 0.8 - 500µm, 380 - 750nm, and 0.01 - 10nm, do not fall within the UV range and are associated with other spectroscopic techniques.

Rate this question:

1
3.

Which of the following compounds does not absorb light in the UV/visible spectrum?
- Aspirin
- Paracetamol
- Chloral hydrate
- Phenobarbitone
Correct Answer

A. Chloral hydrate

Explanation

Chloral hydrate does not absorb light in the UV/visible spectrum because it lacks any chromophores or conjugated systems that are responsible for absorbing light in that range. Chromophores are groups of atoms within a molecule that have delocalized electrons, allowing them to interact with light and absorb specific wavelengths. Aspirin, Paracetamol, and Phenobarbitone all contain chromophores or conjugated systems, which enable them to absorb light in the UV/visible spectrum. Therefore, Chloral hydrate is the compound that does not absorb light in this range.

Rate this question:
4.

In UV absorption spectroscopy, which of the following statements are true?
- σ→σ* transitions are lower in energy than π→π* transitions
- A conjugated systems of double bonds in a molecular shifts the a absorption maxima to higher wavelengths
- σ→σ* transitions are higher in energy than π→π* transitions
- B and C
Correct Answer

A. A conjugated systems of double bonds in a molecular shifts the a absorption maxima to higher wavelengths

Explanation

Conjugated systems of double bonds in a molecule shift the absorption maxima to higher wavelengths. This is because the delocalization of electrons in conjugated systems allows for the formation of lower energy molecular orbitals, resulting in longer wavelength absorptions. This phenomenon is commonly observed in UV absorption spectroscopy.

Rate this question:
5.

A compound X is characterized in its electronic spectrum by an absorption with λ_max = 217 nm (ε_max = 21 000 dm³ mol^–1 cm^–1). Of the compounds given below, X is most likely to be:
- Buta-1,3-diene
- β-carotene.
- Ethanol.
- Water.
Correct Answer

A. Buta-1,3-diene

Explanation

The correct answer is buta-1,3-diene. This is because buta-1,3-diene is a conjugated system of double bonds, which is known to exhibit strong absorption in the UV-Vis region. The absorption at λmax = 217 nm with εmax = 21,000 dm3 mol-1 cm-1 indicates a highly conjugated system, which is characteristic of buta-1,3-diene. β-carotene is also a conjugated system, but its absorption maximum is typically around 450-550 nm, not 217 nm. Ethanol and water do not have conjugated systems and would not exhibit such strong absorption in the UV-Vis region.

Rate this question:

1

Quiz Review Timeline (Updated): Mar 14, 2023 +

Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

Current Version
Mar 14, 2023

Quiz Edited by
ProProfs Editorial Team
Oct 10, 2018

Quiz Created by
Rajju

Pa III (Pr) CA II

Beer’s Law (or the Beer-Lambert Law) is . . .

Quiz Preview

Which of the following wavelength ranges is associated with UV spectroscopy?

Which of the following compounds does not absorb light in the UV/visible spectrum?

In UV absorption spectroscopy, which of the following statements are true?

A compound X is characterized in its electronic spectrum by an absorption with λ_max = 217 nm (ε_max = 21 000 dm³ mol^–1 cm^–1). Of the compounds given below, X is most likely to be:

Pa III (Pr) CA II

Beer’s Law (or the Beer-Lambert Law) is . . .

Quiz Preview

Which of the following wavelength ranges is associated with UV spectroscopy?

Which of the following compounds does not absorb light in the UV/visible spectrum?

In UV absorption spectroscopy, which of the following statements are true?

A compound X is characterized in its electronic spectrum by an absorption with λmax = 217 nm (εmax = 21 000 dm3 mol–1 cm–1). Of the compounds given below, X is most likely to be:

A compound X is characterized in its electronic spectrum by an absorption with λ_max = 217 nm (ε_max = 21 000 dm³ mol^–1 cm^–1). Of the compounds given below, X is most likely to be: