The max of ephedrine HCl and Chlorocresol are 257 nm and 279 nm respectively and the specific absorptivity values in 0.1M HCl solution are: Ephedrine HCl at 257nm=9.0 Chlorocresol at 257nm=20 Ephedrine HCl at 279nm=0 Chlorocresol at 279nm=105 Calculate the concentration of ephedrine HCl and Chlorocresol in a batch of Ephedrine HCl injection, diluted 1 to 25 with water, giving the following absorbance values in 1 cm cells. (A_(279(total)=0.424,A_(257(total))=0.97) Ans. C. Ephedrine HCl in the injection =2.475 gm/100ml C Chlorocresol=0.1010gm/100ml

To solve this problem, we can use the Beer-Lambert Law, which states that the absorbance of a solution is directly proportional to the concentration of the solute in the solution. The equation for the Beer-Lambert Law is:

A = ε \* c \* l

where A is the absorbance, ε is the molar absorptivity, c is the concentration, and l is the path length.

Given the absorbance values and the molar absorptivity values, we can set up two equations to solve for the concentration of ephedrine HCl and Chlorocresol in the injection.

Let's denote the concentration of ephedrine HCl as C1 and the concentration of Chlorocresol as C2.

For ephedrine HCl at 279 nm:
A1 = ε1 \* C1 \* l
0.424 = 0 \* C1 \* 1
C1 = 0.424 / 0 = 0

For Chlorocresol at 257 nm:
A2 = ε2 \* C2 \* l
0.97 = 20 \* C2 \* 1
C2 = 0.97 / 20 = 0.0485 M

Since the injection was diluted 1 to 25, the concentration of ephedrine HCl and Chlorocresol in the injection would be 25 times the concentration in the diluted solution.

C1 = 0 \* 25 = 0
C2 = 0.0485 M \* 25 = 1.2125 M

To convert the concentration from M to gm/100ml, we need to multiply by the molar mass of the compound.

The molar mass of ephedrine HCl is 106.15 g/mol and the molar mass of Chlorocresol is 151.16 g/mol.

C1 = 0 \* 106.15 = 0 gm/100ml
C2 = 1.2125 M \* 151.16 g/mol = 183.5 gm/100ml

Therefore, the concentration of ephedrine HCl in the injection is 0 gm/100ml and the concentration of Chlorocresol is 183.5 gm/100ml.