Instrumental Analysis Final Exam questions with
verified answers
1 eV = ____ Ans✓✓✓ 1.602x10^-19 J
A variety of methods are used to create ions in MS, ____ Ans✓✓✓
mostly positive ions
Adduct Formation: polar molecules that do not have acidic or basic
sites can be charged through formation of adducts Ans✓✓✓ -negative
ions through Cl- ions
-positive ions through Na+, Li+, NH4+, or other cationic species
-can cause background interference
Adducts are often useful in identifying whether a ____ Ans✓✓✓
sample is a mixture or even in determining the molecular mass of the
constituents in a mixture
advantages of creating multiply charged ions in ESI Ans✓✓✓ -improves
sensitivity
-allows the analysis of high molecular weight molecules using mass
analyzers with low mass limit
All odd-electron ions have even m/z values unless ____ Ans✓✓✓ they
contain an odd number of nitrogen
, All these collisions will ____ (the resulting spectrum will be extremely
hard to interpret) Ans✓✓✓ increase the complexity of the ions
produced and hence the spectrum
All these various fragmentation pathways give rise to the _____
Ans✓✓✓ mass spectrum of the compound
An eV is the energy associated with an ____ Ans✓✓✓ electron moving
through a potential difference of one volt
An eV is the quantity of ____ Ans✓✓✓ energy that needs to be
imparted to an electron to accelerate it by one volt potential difference
At 300° K the mean free path, L = Ans✓✓✓ 0.66/P
Atomic Mass Unit (amu) value Ans✓✓✓ 1.66x10^-24 g
Buffers that are volatile and don't form ion pairs give ____ Ans✓✓✓
maximum ESI efficiency
Charged Residue Model Ans✓✓✓ -evaporation of analyte from the
micro-droplet surface takes place continuously
verified answers
1 eV = ____ Ans✓✓✓ 1.602x10^-19 J
A variety of methods are used to create ions in MS, ____ Ans✓✓✓
mostly positive ions
Adduct Formation: polar molecules that do not have acidic or basic
sites can be charged through formation of adducts Ans✓✓✓ -negative
ions through Cl- ions
-positive ions through Na+, Li+, NH4+, or other cationic species
-can cause background interference
Adducts are often useful in identifying whether a ____ Ans✓✓✓
sample is a mixture or even in determining the molecular mass of the
constituents in a mixture
advantages of creating multiply charged ions in ESI Ans✓✓✓ -improves
sensitivity
-allows the analysis of high molecular weight molecules using mass
analyzers with low mass limit
All odd-electron ions have even m/z values unless ____ Ans✓✓✓ they
contain an odd number of nitrogen
, All these collisions will ____ (the resulting spectrum will be extremely
hard to interpret) Ans✓✓✓ increase the complexity of the ions
produced and hence the spectrum
All these various fragmentation pathways give rise to the _____
Ans✓✓✓ mass spectrum of the compound
An eV is the energy associated with an ____ Ans✓✓✓ electron moving
through a potential difference of one volt
An eV is the quantity of ____ Ans✓✓✓ energy that needs to be
imparted to an electron to accelerate it by one volt potential difference
At 300° K the mean free path, L = Ans✓✓✓ 0.66/P
Atomic Mass Unit (amu) value Ans✓✓✓ 1.66x10^-24 g
Buffers that are volatile and don't form ion pairs give ____ Ans✓✓✓
maximum ESI efficiency
Charged Residue Model Ans✓✓✓ -evaporation of analyte from the
micro-droplet surface takes place continuously
