Spectroscopy quiz 1

Which one is not correct

• Spectroscopy is the study of spectrum

• Spectroscopy is the study of interaction of one radiation with other radiation

• Spectroscopy is the study of interaction of radiation with matter

• the radiation used is EMR

Which of the following statements is correct?

• Infrared radiation has a shorter wavelength than visible light.

• Infrared radiation has a lower wavenumber than visible light.

• Ultraviolet radiation has a longer wavelength than infrared radiation.

• Microwave radiation possesses more energy than infrared radiation.

Which statement is correct?

• Wavelength is directly proportional to frequency.

• Wavelength is directly proportional to energy.

• Wavenumber is directly proportional to wavelength.

• Wavenumber is directly proportional to energy.

The wavelength of an absorption is 495 nm. In what part of the electromagnetic spectrum does this lie?

• Radiowave

• Infrared

• Ultraviolet-visible

• Microwave

A solution of a dye absorbs light of wavelength 480 nm, and for this absorption, the extinction coefficient is 18600 dm³ mol^–1 cm^–1. A sample of the dye of unknown concentration is placed in an optical cell of path length 1 cm and the absorbance reading is 0.18. What is the concentration of the solution?

• 3.0 × 10^–4 mol dm^–3

• 0.026 mol dm^–3

• 2.0 × 10^–8 mol dm^–3

• 9.7 × 10^–6 mol dm^–3

The frequency of a transition is 3.1 × 10^10 Hz. What is the energy of this transition?

• 2.0 × 10^–23 J

• 2.1 × 10^–44 kJ

• 2.0 × 10^–23 kJ

• 2.1 × 10^–44 J

UV range from 10 to 200 nm is known as

• Far UV

• Near UV

• Mid UV

• None of the above

A photon of wavenumber 100 cm^-1 has a wavelength of

• 1 mm

• 1 m

• 1000 nm

• 100 m

What is the name of an instrument used to measure the absorbance of a coloured compound in solution?

• Calorimeter.

• Colorimeter.

• Coulometer.

• Colourmeter.

A solution of X of concentration 0.010 mol dm–3 gives an absorbance of 0.5. What concentration is a solution of X which gives an absorbance reading of 0.25? Assume that the same optical cell is used for both readings.

• 0.020 mol dm^–3

• 0.050 mol dm^–3

• 0.010 mol dm^–3

• 0.0050 mol dm^–3