jagomart
digital resources
picture1_Instrumental Methods Of Analysis Pdf 87013 | Instrumental Methods Of Chemical Analysis 1


 221x       Filetype PDF       File size 0.13 MB       Source: www.philadelphia.edu.jo


File: Instrumental Methods Of Analysis Pdf 87013 | Instrumental Methods Of Chemical Analysis 1
questions on instrumental methods of analysis 1 which one of the following techniques can be used for the detection in a liquid chromatograph a ultraviolet absorbance or refractive index measurement ...

icon picture PDF Filetype PDF | Posted on 14 Sep 2022 | 3 years ago
Partial capture of text on file.
                                           Questions on Instrumental Methods of Analysis 
                                                                                 
                        1. Which one of the following techniques can be used for the detection in a liquid  
                             chromatograph? 
                         
                                   a.  Ultraviolet absorbance or refractive index measurement. 
                                   b.  Increase in temperature 
                                   c.  Ionization in flame 
                                   d.  Thermal conductivity 
                                   Answer = a 
                        2.  Considering high performance liquid chromatography, which one of the following     
                                   statements is FALSE? 
                         
                                    a.    HPLC is suitable for the separation and determination of  the   
                                            nonvolatile (high boiling point) components. 
                                    b.    The stationary phase could be a liquid or a solid. 
                                    c.    Columns longer than 50 meters have been used here to  
                                             increase the efficiency of separation. 
                                    d.      High pressure is used here to decrease the retention time and improve   
                                             the separation of components. 
                                    Answer = c 
                         
                        3.  According to Beer’s law for a colored solution, which one of the following  
                             statements is False? 
                         
                                   (a)   The percent transmission is not directly proportional to the concentration.  
                                   (b)   The absorbance is directly proportional to the concentration. 
                                   (c)   The absorbance does not change when the cell path length (cell  
                                           thickness) increases.  
                                   (d)  When the concentration of the unknown sample is higher than the   
                                           highest concentration in the calibration range, the sample should be   
                                           diluted. 
                                   Answer = b 
                        4.  Deuterium and tungsten lamps are used as a light source in one of the 
                             following techniques.  
                                   (a)  Nuclear magnetic resonance spectrophotometers 
                                   (b)  X-rays diffractometers 
                                   (c)  Gas chromatograph 
                                   (d)   Uv/Visible spectrophotometers 
                        Answer = d 
                        5. Which one of the following arrangements for the sequence of the main components of 
                            a Uv/visible spectrophotometer is Correct? 
                         
                                 (a)   Light source    Monochromator   Sample cell   Detector   Readout    
                                (b)   Light source   Detector   Sample cell  Monochromator   Readout    
                                 (c)   Light source   Sample cell   Detector   Monochromator  Readout         
                                 (d)   Light source    Readout   Sample cell   Detector   Monochromator  
                        Answer = a 
                         
                                                                                1                                                      
          6. Considering the electrochmical cells, which one of the following statements is False? 
              
               (a) Galvanic cell is that in which a spontaneous chemical reaction takes place 
                 and an electrical energy is produced.  
               (b) A nonspontaneous chemical reaction is forced to occur in the  
                     electrolysis cell.  
               (c) The salt bridge is used to allow for the movement of electrons  
                 from the solution of one half cell to the other  
               (d) The cathode is the electrode at which reduction takes place.  
                  
                 Answer = a 
           
          7. which one of the following radiation has the longer wavelength 
            a-  infra red 
            b-  visible 
            c-  x-ray 
            d-  ultra violet 
            e-  gamma rays 
           
          Answer = a 
           
          8. The energy associated with infra red is enough to make 
             a-  electronic transitions 
             b-  vibrational and rotational transitions 
             c-  a full separation of the electron in the outer shell 
             d-  X-ray fluorescence 
             e-  an electron move from an inner orbital 
           
          Answer = b 
           
          9. The moisture in an organic substance is determined by 
           a-  potentiometric titration 
           b-  X-ray fluorescence 
           c-  X-ray absorption  
           d-  Karl Fisher titration 
           e-  Measuring the pH of the system 
          Answer = d 
           
          10. The technique used to identify a functional group in an organic molecule is 
            a-  coulometry 
            b-  X-ray fluorescence 
            c-  Infrared spectrometry 
            d-  Karl Fisher titration 
            e-  Conductimetry 
           
          Answer = c 
           
           
           
           
                                 2                    
                               11. One part per million is the same as  
                                            (a)  1 g/g 
                                            (b)  1 mg/kg  
                                            (c)  1 ng/mg  
                                            (d)  All of the above are correct  
                                      Answer = c 
                                       
                                
                                12.  Narrow line spectra are emitted by 
                                   (a)  hot solids 
                                   (b)  excited polyatomic molecules 
                                   (c)  molecules in the ground molecular state 
                                   (d) excited atoms 
                                       Answer = d 
                                        
                                13.        What are the dimensions of the molar absorptivity in the Beer's law expression ? 
                               (a)  Moles per liter 
                               (b)  Liters per mol.centimeter 
                               (c)  Grams per mole 
                               (d) Micrograms per square centimeter 
                                       Answer = b 
                                        
                               14. The region of the electromagnetic spectrum in which the highest energy 
                                photons are observed is the 
                               (a)  ultraviolet 
                               (b)  infrared 
                               (c)  microwave 
                               (d)  x-ray 
                                       Answer = d 
                                
                                
                               14.  An important advantage of a double-beam spectrophotometer over a single-beam   
                                             spectrophotometer is  that  
                                             (a) it permits cancellation of slow variations of the source power  
                                             (b) it requires same light source for Uv, Vis, and Infra red radiation    
                                             (c) it can be used in conjunction with  rapid response detection systems  
                                            (d) a greater range of wavelengths can be used 
                            Answer = a 
                                
                                
                                
                                
                                
                                                                                                      3                                                                        
                                     15. Grating is a device used in the spectrophotometer to function as 
                                                  (a)  a light source 
                                                  (b)  a monochromator 
                                                  (c)   a detector 
                                                  (d)   a nebulizer 
                               Answer = b 
                                
                                                   
                                         16. Helium rather than argon, often is used as the carrier gas in GLC when TCD is   
                                               used as the detector because,  
                                               (a) He  has a higher ionization potential  
                                               (b) He  is more inert  
                                               (c) He  has stable isotopes which separate and cause a change in column   
                                                     behavior. 
                                               (d) He  has a higher thermal conductivity 
                                
                                           Answer = d 
                                            
                                     
                                        17. To deionize laboratory water by ion-exchange, the best approach employs  
                                               (a)    a column containing a strong acid cation exchanger in the hydrogen form  
                                               (b)    a column containing a strong base anion exchanger in the hydroxyl form 
                                               (c)     a mixed bed column containing a strong acid cation exchanger in the   
                                                        sodium form and a strong base anion exchanger in the hydroxyl  form 
                                                (d)    a mixed bed column containing a strong acid cation exchanger in the    
                                                        hydrogen form and a strong base anion exchanger in the hydroxyl form 
                                Answer = c 
                                
                                        18. Reversed phase HPLC is the technique in which 
                                               (a) stationary phase is solid and mobile phase is liquid. 
                                               (b) the stationary phase is made of very fine particles. 
                                               (c) the stationary phase is non polar and the mobile phase is relatively polar. 
                                               (d) the stationary phase has been silinized with dimethyldichlorosilane. 
                                                
                                               Answer = c 
                                                
                                19.  Considering high performance liquid chromatography, which one of the    
                                                Following statements is FALSE? 
                                                 (a) HPLC is suitable for the separation and detrmination of  the nonvolatile 
                                                       species. 
                                                 (b) The stationary phase used in the HPLC column could be relatively polar or 
                                                       nonpolar liquid.  
                                                 (c) The separation efficiency has been increased by decreasing the particle  
                                                       size of the solid support for the stationary phase. 
                                                 (d) Very long columns have been used here to increase the effecirncy of   
                                                      separation.   
                               Answer = d 
                                
                                                                                                      4                                                                        
The words contained in this file might help you see if this file matches what you are looking for:

...Questions on instrumental methods of analysis which one the following techniques can be used for detection in a liquid chromatograph ultraviolet absorbance or refractive index measurement b increase temperature c ionization flame d thermal conductivity answer considering high performance chromatography statements is false hplc suitable separation and determination nonvolatile boiling point components stationary phase could solid columns longer than meters have been here to efficiency pressure decrease retention time improve according beer s law colored solution percent transmission not directly proportional concentration does change when cell path length thickness increases unknown sample higher highest calibration range should diluted deuterium tungsten lamps are as light source nuclear magnetic resonance spectrophotometers x rays diffractometers gas uv visible arrangements sequence main spectrophotometer correct monochromator detector readout electrochmical cells galvanic that sponta...

no reviews yet
Please Login to review.