# Tag Info

3

Warning: This is also a homework question. However, this is more like mathematics (geometry) than chemistry, I decided to help you. Nonetheless, please keep in mind that we won't help you in all future perspectives, if you do not show your effort to solve the problem, regardless more mathematics involved. As M. Farooq pointed out that this problem can be ...

3

If we take 1st and last points on your graph we'd see that: At concentration $\pu{350ppm}$ your detector shows number $45$ At concentration around $0$ your detector shows number around $0$ So what if detector shows $175$ (which is $0.5*(350-0))$? You may conclude that the concentration is $\pu{22.5ppm}$ (which $0.5*(45-0)$) Calibration curve gives you ...

4

Suppose it is a calibration curve of high performance liquid chromatography (HPLC) to determine concentration of chloride ion in unknown solutions. The detector is sensitive to charge ions, which gave the peaks, area of which is proportional to concentration of ions. I assume each peak area is highly specific for ion in interest. First you make a calibration ...

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Your link almost certainly explains the alkanes. It says commercial paraffins are mostly in the 22 to 38 range That's exactly the range we are seeing in the chromatogram. I'd consider this the answer.

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I assume your teacher explained the HPLC separation. If injected a mixture of four ions you will get four peaks. Each peak has an area, which is proportional to the concentration of the substance. Imagine you wanted to determine the concentration of chloride ions in your tap water. What you would do is that you will prepare several known concentrations of ...

3

The line goes according to : $y = 0.1312~x$ ; In other words the area of the peak is equal to $0.1312$ times the concentration of chloride in ppm. This result is extremely useful. If for example, in a later measurement you obtain a peak whose area is $y = 35$, it means that the concentration $x$ of chloride ion responsible of this peak is : $x = 35/0.1312 = ... 1 Question: Would the hexane and ethyl acetate be considered the mobile phase/solvent? Answer is yes: Hexane/ethyl acetate systems ($0$to$100\%\$ ethyl acetate in hexane) are frequently used mobile phases for TLC technique. However, as Waylander pointed out in his comment: The type of mobile phase really depends on what the substrate and product are. It is ...

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Your advisor is making a pretty dangerous assumption (although sometimes pharma people do it). The assumption is that the impurity is structurally similar to the main compound and its UV-Vis spectrum is almost similar i.e., their extinction coefficients are the same. The idea in your formula is that the calibration curve for A will be same as B. Well that ...

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