Quiz. Homework 4. Please highlight the correct answer. 1.- What is the maximum number of EPR signals that would be expected from the radical molecule below given that the nuclear spin of hydrogen is...

This a multiple choice question quiz.


Quiz. Homework 4. Please highlight the correct answer. 1.- What is the maximum number of EPR signals that would be expected from the radical molecule below given that the nuclear spin of hydrogen is ½? Group of answer choices 13 0 2 9 2.- Which is the optimal technique to analyse particles whose particle size is of similar magnitude to that of the incident wavelength? Circular Dichroism Nephelometry Turbidimetry Fluorescence 3.- Select the false statement about Raman Spectroscopy The wavelengths of the absorption bands in Raman and IR do not always coincide All molecules that have a net dipole moment when vibrating Stokes and antistokes lines present different intensity A fraction of the scattered radiation may not be the same frequency as the incident radiation 4.- In Quadrupole MS, a mass scan is made by, which of the following methods? keeping the RF:DC ratio constant, but altering the magnitude of both terms putting an electrostatic analyser between the ion source and the detector altering the RF, but keeping the DC constant altering the DC, but keeping the RF constant 5.- In the Moving Belt Interface, the purpose of the Infra-red heater is to achieve which of the following? Desolvate the eluent Enable the operator to view the sample Produce gaseous ions Make the belt run faster 6.- Which ONE of the following statements about the advantages of 13C NMR is FALSE? Good methods allow decoupling of 13C and protons 13C NMR gives information about the molecule’s backbone not periphery The chemical shift range of 13C NMR is less than that of proton NMR Homonuclear spin-spin coupling is not encountered because 13C abundance is low 7.- What is the number of lines that can be theoretically seen in the proton NMR of CH3CH2CH2I  as a result of protons in the central CH2 coupling with protons either side of it? 9 12 6 7 8.- The theoretical number of modes of vibration in the CO2 molecule is FOUR. How many lines are actually seen in the IR spectra? 5 3 2 1 9.- Fluorescence is most likely to occur in compounds where the lowest energy transition is which of the following? Π⟶ΠΠ⟶Π* n⟶Πn⟶Π* Π⟶nΠ⟶n* n⟶nn⟶n* 10.- Which ONE of the following techniques can be used as a sharp line source in  Atomic Absorption Spectroscopy? Hollow cathode lamp Graphite furnace Constant current, low voltage arcs High voltage AC spar 11.- In flame photometry, lithium can be analysed by means of its emission line at 671 nm. Calculate the wavenumber. 6.7 x 10-7 cm-1 14,903 cm-1 67,100 cm-1 149.03 cm-1 12.- Which ONE of the following preparation techniques is often used for analysis of silicate materials? Lithium metaborate fusion Reduction using hydroxylamine sulphate Dissolution in deionised water Wet oxidation with nitric acid