Recent questions tagged modern-pharmaceutical-analysis

What is shielding in NMR? A. Using a curved piece of metal to block an opponent’s attack B. Putting metal around an Rf source C. When the magnetic moment of an atom blocks the full induced magnetic field from surrounding nuclei D. Blocking parts of a molecule from Rf radiation

Description : What is shielding in NMR? A. Using a curved piece of metal to block an opponent’s attack B. Putting metal around an Rf source C. When the magnetic moment of an atom blocks the full induced magnetic field from surrounding nuclei D. Blocking parts of a molecule from Rf radiation

Last Answer : When the magnetic moment of an atom blocks the full induced magnetic field from surrounding nuclei

Chemical shifts (δ) are typically reported in units of A. Gauss (G) B. Millitesla per meter (mT/m) C. Parts per million (ppm) D. Percent (%)

Description : Chemical shifts (δ) are typically reported in units of A. Gauss (G) B. Millitesla per meter (mT/m) C. Parts per million (ppm) D. Percent (%)

Last Answer : Parts per million (ppm) 

Which of the following names refers to the highest energy spin state of an ¹H nucleus in a magnetic field? A. Spin-up B. Spin-down C. Parallel D. |+½>

Description : Which of the following names refers to the highest energy spin state of an ¹H nucleus in a magnetic field? A. Spin-up B. Spin-down C. Parallel D. |+½>

Last Answer : Spin-down

he dipole magnetic moment (μ) is directly proportional to nuclear spin (I), connected by a constant called the A. Gyromagnetic ratio (γ) B. Planck's constant (h) C. Nuclear susceptibility (χ) D. Chemical shift (δ)

Description : he dipole magnetic moment (μ) is directly proportional to nuclear spin (I), connected by a constant called the A. Gyromagnetic ratio (γ) B. Planck's constant (h) C. Nuclear susceptibility (χ) D. Chemical shift (δ) 

Last Answer : Gyromagnetic ratio (γ)

In mass spectrometry, fragmentation of ions is achieved through? A. Ionization B. Splitting C. Solubilization D. Coupling

Description : In mass spectrometry, fragmentation of ions is achieved through? A. Ionization B. Splitting C. Solubilization D. Coupling

Last Answer : Ionization

Which of the following techniques would be most useful to identify and quantify the presence of a known impurity in a drug substance? A. NMR B. MS C. IR D. HPLC

Description : Which of the following techniques would be most useful to identify and quantify the presence of a known impurity in a drug substance? A. NMR B. MS C. IR D. HPLC

Last Answer : IR

HPLC is an abbreviation for? A. High Profit Liquid Chromatography B. High Pressure Liquid Chromatography C. Higher Performance Low Chromatography D. Higher Profit Low Chromatography

Description : HPLC is an abbreviation for? A. High Profit Liquid Chromatography B. High Pressure Liquid Chromatography C. Higher Performance Low Chromatography D. Higher Profit Low Chromatography

Last Answer : High Pressure Liquid Chromatography

The basis of the technique of chromatography for separating components of a mixture is? A. the differing movement of particles of different mass in an electrical field B. the interaction of the components with a stationary and a mobile phases C. the absorption of infrared radiation by the components. D. the deflection of charged particles in a magnetic field.

Description : The basis of the technique of chromatography for separating components of a mixture is? A. the differing movement of particles of different mass in an electrical field B. the interaction of the ... infrared radiation by the components. D. the deflection of charged particles in a magnetic field. 

Last Answer : the interaction of the components with a stationary and a mobile phases

In a chromatographic separation, which of the following is most appropriate for the qualitative identification of a substance? A. Relative retention factor B. Retention factor C. Retention time D. Resolution

Description : In a chromatographic separation, which of the following is most appropriate for the qualitative identification of a substance? A. Relative retention factor B. Retention factor C. Retention time D. Resolution 

Last Answer : Retention time

Column efficiency is measured in terms of number of theoretical plates, which is: A. Inversely related to height equivalent to theoretical plates B. Directly related to the peak width C. Directly related to height equivalent to theoretical plates D. Inversely related to the peak width

Description : Column efficiency is measured in terms of number of theoretical plates, which is: A. Inversely related to height equivalent to theoretical plates B. Directly related to the peak width C. Directly related to height equivalent to theoretical plates D. Inversely related to the peak width

Last Answer : Inversely related to height equivalent to theoretical plates 

Which one of the following is necessary for mass spectrometry to occur? A. Loss of an electron B. Change of alignment of a proton in a magnetic field C. A molecular vibration D. Excitation of an electron from the ground state to a higher energy state

Description : Which one of the following is necessary for mass spectrometry to occur? A. Loss of an electron B. Change of alignment of a proton in a magnetic field C. A molecular vibration D. Excitation of an electron from the ground state to a higher energy state

Last Answer : Loss of an electron

The base peak in mass spectrum is? A. The lowest mass peak B. The peak corresponding to the parent ion C. The highest mass peak D. The peak set to 100% relative intensity

Description : The base peak in mass spectrum is? A. The lowest mass peak B. The peak corresponding to the parent ion C. The highest mass peak D. The peak set to 100% relative intensity

Last Answer : The peak set to 100% relative intensity

Signal splitting in NMR arises from? A. Shielding effect B. Spin-spin decoupling C. Spin-spin coupling D. Deshielding effecr

Description : Signal splitting in NMR arises from? A. Shielding effect B. Spin-spin decoupling C. Spin-spin coupling D. Deshielding effecr

Last Answer : Spin-spin coupling

1H nuclei located near electronegative atoms tend to be ______ relative to 1H nuclei A. Shielded B. Deshielded C. Resonanced D. Split

Description : 1H nuclei located near electronegative atoms tend to be ______ relative to 1H nuclei A. Shielded B. Deshielded C. Resonanced D. Split

Last Answer : Deshielded

Which of the following is used as a carrier gas in gas chromatography A. Carbon dioxide B. Oxygen C. Helium D. Methane

Description : Which of the following is used as a carrier gas in gas chromatography A. Carbon dioxide B. Oxygen C. Helium D. Methane

Last Answer : Helium

Which of the following is an example of bulk property or general detector in HPLC A. Fluorescence detector B. Refractive index detector C. Electrochemical detector D. UV-Visible detector

Description : Which of the following is an example of bulk property or general detector in HPLC A. Fluorescence detector B. Refractive index detector C. Electrochemical detector D. UV-Visible detector

Last Answer : Refractive index detector

What is a chromophore? A. A coloured compound B. A group of atoms in compound responsible for electromagnetic radiation C. A group of atoms in a compound responsible for the absorption of electromagnetic radiation D. A group of atoms in coloured compound

Description : What is a chromophore? A. A coloured compound B. A group of atoms in compound responsible for electromagnetic radiation C. A group of atoms in a compound responsible for the absorption of electromagnetic radiation D. A group of atoms in coloured compound

Last Answer : A group of atoms in a compound responsible for the absorption of electromagnetic radiation 

Infrared spectroscopy provides valuable information about A. Molecular weight B. Melting point C. Conjugation D. Functional groups

Description : Infrared spectroscopy provides valuable information about A. Molecular weight B. Melting point C. Conjugation D. Functional groups

Last Answer : Functional groups

To improve a chromatographic separation, you must A. Increase the number of theoretical plates on the column. B. Increase the height of the theoretical plates on the column. C. Increase both the number and the height of the theoretical plates on the column. D. Decrease both the number and the height of the theoretical plates on the column

Description : To improve a chromatographic separation, you must A. Increase the number of theoretical plates on the column. B. Increase the height of the theoretical plates on the column. C. Increase both the number ... the column. D. Decrease both the number and the height of the theoretical plates on the column

Last Answer : Increase the number of theoretical plates on the column

The fluid exiting a chromatographic column is called the A. eluent B. eluate C. analyte D. elution

Description : The fluid exiting a chromatographic column is called the A. eluent B. eluate C. analyte D. elution

Last Answer : eluate

Mobile phase can be A. gas or liquid B. solid or liquid C. only solid D. gas only

Description : Mobile phase can be A. gas or liquid B. solid or liquid C. only solid D. gas only 

Last Answer : gas or liquid

Chromatography can be used to A. form mixtures B. change mixture compositions C. separate mixtures into pure substances D. all of these

Description : Chromatography can be used to A. form mixtures B. change mixture compositions C. separate mixtures into pure substances D. all of these

Last Answer : separate mixtures into pure substances

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