Question

QUESTIONS 1. What are dependent variables of a van-Deemter plot 2. What is a dynamic range problem and how does it affect the efficiency of a chromatographic analysis? 3. Why does a TCD respond to all analytes except the carrier gas? 4. What are the relative advantages and disadvantages of packed and open tubular columns in GC? 5. Predict the elution order of the following analytes from a Carbowax 20 M column: hexane. acetaldehyde, octane, benzene, toluene, ethylbenzene, O-xylene and butanol?

Answer 1

Following is the - complete : Answer -&- Explanation: for the first question ( i.e. Question - 1 ) , of the given: Question Set.....in.....typed & image format...

$\Rightarrow$Answer:

Van Deemter plot, usually have: ONLY One: dependent variable: i.e. H ( Height Equivalent of Theoritical Plate, i.e. plate height ), versus: which the: linear velocity ( i.e. velocity of the mobile phase ), is plotted in a standard graph.

Whereas, the value of height of plate ( H ) ,is the dependent variable: of other two: dependent variables, viz. B, and

( C_s and C_m ).   All of the following: i.e. H, B, and C : are dependent variables, i.e. dependent on the linear velocity ( u )

$\Rightarrow$Explanation:

Following is the complete Explanation: for the above: Answer,...in...image format....

Explanation -- Step We have the following: Var Seemfor Equation : HA+&+ [6+ Cola --0 Where: ③ H = Plate Height, or Height Equivalent Theoretical plate. A e Eddig Eddy biffusion = remains constant B = Longitucinal diffusion term, which is a dependent E variable, of Linear relocity ("). Cg = Resistance to Mars Transfer, due to the Stationary fshare.

. Cm = Resistance to mass transfor, due to Mobile - phase. Du = hinen velocity of Mobile phase Note: As we can see above; H', is a dependent variable of other two dependent variables , irel B es, and We can see ak Cn terms ... ferms... Step (2):

- This following a will be as Van Denter Graph. (standand). - 4 (Plate Height) (HET Par lute height - a (linear relocity)