Test Yourself : Chapter 64 Instrumental analytical methods

Which of the following colour filters is suitable for use in colorimetric measurement of a sample sodium chromate solution?

• A. Purple filter
• B. Red filter
• C. Green filter
• D. Orange filter

Which of the following statements concerning colorimetry are correct?

(1) A colorimeter is used to carry out colorimetry.

(2) It determines the concentration of a coloured species by measuring the amount of light its sample solution transmits.

(3) The lower the concentration of a solution of the coloured species, the lower is its absorbance.

• A. (1) and (2) only
• B. (1) and (3) only
• C. (2) and (3) only
• D. (1), (2) and (3)

Which of the following characteristic infrared radiation wavenumber ranges can be used to distinguish between propan-1-ol and propanoic acid?

(1) The wavenumber range 1680–1800 cm⁻¹

(2) The wavenumber range 2500–3300 cm⁻¹

(3) The wavenumber range 3230–3670 cm⁻¹

• A. (1) and (2) only
• B. (1) and (3) only
• C. (2) and (3) only
• D. (1), (2) and (3)

The infrared spectrum of compound W is shown in the diagram. Which of the following bonds is most likely to be present in W?

• A. C≡C
• B. C≡N
• C. C=O
• D. N–H

P is an acyclic compound (with a molecular formula C₃H₈O). Upon heating with excess acidified potassium dichromate solution under reflux, P can be converted to compound Q. The infrared spectrum of Q is shown in the diagram. What is the condensed structural formula of P?

• A. CH₃CHCH₂O
• B. CH₃OCH₂CH₃
• C. CH₃CH₂CH₂OH
• D. CH₃CH(OH)CH₃

Which of the following ions would be deflected to the least extent in a mass spectrometer?

• A. C₆H₅³⁷Cl²⁺

• B. C₆H₅³⁵Cl²⁺

• C. ⁺CH₂⁸¹Br

• D. ⁺CH₂⁷⁹Br

Which of the following compounds can produce a peak at m/z = 57 in their mass spectra?

(1) CH₃CH₂CH₂CH₂CH₃

(2) CH₃COCH₂CH₂CH₃

(3) CH₃CH₂COCH₂CH₂CH₃

• A. (1) and (2) only
• B. (1) and (3) only
• C. (2) and (3) only
• D. (1), (2) and (3)

X is a carbon compound with a carbonyl group and not more than four carbon atoms. Its mass spectrum is shown in the diagram. Which of the following statements concerning X are correct?

(1) The relative molecular mass of X is 58.

(2) The peak at m/z = 43 is due to the fragment ion CH₃CO⁺.

(3) X is an aldehyde.

• A. (1) and (2) only
• B. (1) and (3) only
• C. (2) and (3) only
• D. (1), (2) and (3)