Question

1. The Marquis CST reagent is applied to an unknown drug and the solution turns green. Next, Cobalt Thiocyanate reagent is applied and the solution turns reddish-orange. For the same unknown drug, Mecke’s reagent turns the solution a greenish black color.

The identity of this unknown drug could possibly be _________________________.

2. An unknown sample compound (labeled H), and standards for two known compounds A and B, are subjected to TLC analysis. The results of the TLC analysis are shown below.

Component	Replicate (n)	Rf Value
Unknown Sample H	1	2.23
Unknown Sample H	2	2.32
Unknown Sample H	3	2.28
Standard for Compound A	1	3.10
Standard for Compound A	2	3.25
Standard for Compound A	3	3.12
Standard for Compound B	1	1.59
Standard for Compound B	2	1.51
Standard for Compound B	3	1.55

Find the mean R_f value and standard deviation for the unknown and standards. Enter all calculation results in the table. Show example calculations for one component in the space above the table. (You can use Excel, but print out and attach all spreadsheet calculations to hand in with this Pre-Lab assignment.)

Component (n = 3)	Mean Rf Value	Standard Deviation
Unknown Sample H
Standard for Compound A
Standard for Compound B

Conduct a Student’s t test to determine if there is a statistically significant difference between your sample and each standard. Use a 95 % confidence interval and the null hypothesis: “The standard mean is not different from the sample mean.” Use Table 4-4 on p. 84 of your textbook to look up Student’s t values. Enter all calculation results in the table below. Show example calculations for one Student t test in the space above the table. (You can use Excel, but print out and attach all spreadsheet calculations to this Pre-Lab assignment.)

Components Tested	spooled	Calculated t	t from Table 4-4	Significant difference?
Unknown H and Standard A
Unknown H and Standard B

What can you conclude about the possible identity of the unknown based on these statistical tests? Explain your answer.

Answer 1

Following is the solution and answer to the first question (i.e. question- 1) of the given ...question set...

Answer:

Most possible name of the unknown drug would be .... 2C-B drug substance....

Reasons:

1. 2C-B solution turns green in Marquis reagent.....
2. 2C-B solution turns Greenish-Black ...when in contact with Mecke reagent

Unsure about 2C-B colour change ...when in Cobalt Thiocyanate​.

For the above reasons...I think, the name of the unknown drug (i.e. substance) would most possibly be: 2C-B....... (answer).