Suppose we are running a Gas Chromatography for a mixture of standard alkanes (C5-C18) in hexane...

Suppose we are running a Gas Chromatography for a mixture of standard alkanes (C5-C18) in hexane solvent. How do we determine which alkanes are present in the standard from the chromatogram?

Solutions

Expert Solution

In gas chromatography, the mobile phase is a gas usually nitrogen, helium, argon or hydrogen. The analyte can be either naturally volatile or volatile derivative. The stationary phase can be either nonvolatile liquid bound to a solid support or underivatized solid particles. Depending on the interaction with the stationary phase the components in the analyte are separated. The interacting force can be vanderwaals, dipole-dipole or hydrogen bonding. If a component is interacting strongly with the stationary phase then it will be retained for a long time and will have long retention time as compared to a component which is weakly interacting. And components of similar polarity elute in the order of volatility. Thus lower boiling alkanes have short retention time than higher boiling alkanes. The boiling point of straight chain alkanes follows a linear relationship, nearly 20-30 degree Celsius rise for each carbon added to the chain. Thus C5 has a low boiling point and get eluted first as compared to C18

queen_honey_blossom answered 1 year ago

Next > < Previous

Related Solutions

) A mixture of liquid alkanes, being stored at 15.00°C, contains n-hexane, cyclopentane, and isoheptane. Data...

) A mixture of liquid alkanes, being stored at 15.00°C, contains n-hexane, cyclopentane, and isoheptane. Data on these alkanes is provided below. Alkane Formula Amount (w/w%) ΔHvap (kJ/mol) P* at 20.00°C (kPa) n-hexane C6H14 42.4% 31.11 16.44 cyclopentane C5H10 56.1% 28.86 34.61 isoheptane C7H16 1.5% 34.89 5.300 a) What is the saturated vapour pressure, in kPa, of each pure component at 15.00°C? b) What is the vapour pressure of each component, in kPa, above the liquid mixture at equilibrium? c)...

A gas mixture containing 60% N2 and the balance n-hexane flows through a pipe at a...

A gas mixture containing 60% N2 and the balance n-hexane flows through a pipe at a rate of 200m3/hr. The pressure is 2atm absolute and the temperature is 100 C. a) What is the molar flow rate of the gas in kmol/hr? b) Is the gas saturated? Show calculations (hint: use vapor pressure of hexane at 100 C) c) If 80% of n-hexane is condensed (and leaves as a liquid), how much of vapor is leaving and what is its...

A gas mixture containing 80.0 mole% N2 and the balance n-hexane flows through a pipe at...

A gas mixture containing 80.0 mole% N2 and the balance n-hexane flows through a pipe at a rate of 100.0 m3/h. The pressure is 2.00 atm absolute and the temperature is 140.0°C. a. What is the molar flow rate of the gas? b. To what temperature would the gas have to be cooled at constant pressure in order to begin condensing hexane? c. To what temperature would the gas have to be cooled at constant pressure in order to condense...

What is the advantage of using an internal standard in a gas chromatography experiment?

In Preparative Gas Chromatography with a mixture, 3-pentanol was found to have a starting collection time...

In Preparative Gas Chromatography with a mixture, 3-pentanol was found to have a starting collection time of 3.81 minutes and an ending collection time of 5.38 min. What is its retention time? Which compounds have higher/lower retention times, and what are some factors that affect retention time?

The dew-point temperature of a gas mixture with a molar composition of 40.0% n-hexane, 25.0% n-heptane,...

The dew-point temperature of a gas mixture with a molar composition of 40.0% n-hexane, 25.0% n-heptane, and 35.0% air at 1.00 atm.

Suppose you have been given the task of distilling a mixture of hexane + toluene. Pure...

Suppose you have been given the task of distilling a mixture of hexane + toluene. Pure hexane has a refractive index of 1.375 and pure toluene has a refactive index of 1.497. You collect a distillate sample which has a refractive index of 1.441. Assuming that the refractive index of the hexane + toluene mixture varies linearly with mole fraction, what is the mole fraction of hexane in your sample?

Gas Chromatography How are compounds separated by GC? What kind of information do we get from...

Gas Chromatography How are compounds separated by GC? What kind of information do we get from GC/MS analysis?

Suppose in December 2019, the average and standard deviation of gas price at gas stations were...

Suppose in December 2019, the average and standard deviation of gas price at gas stations were 136.5 and 6 ¢/liter respectively. A random sample of n = 36 gas stations is selected from the population and the price per liter of gas is determined for each. a) Describe the distribution of the average gas price determined for this sample gas stations. What are the values of mean and standard deviation for this distribution? b) What is the probability that the...

Suppose that we performed the algorithm SELECT whose running time is O(n) on 133 elements, and...

Suppose that we performed the algorithm SELECT whose running time is O(n) on 133 elements, and found the median of medians x by making groups of 5 elements. What is the maximum number of elements which are guaranteed to be greater than equals to x (without counting x, itself)?

Subjects