Can someone please show the steps used to solve this problem? I know the answer
ID: 780413 • Letter: C
Question
Can someone please show the steps used to solve this problem? I know the answer is 0.143M but I can't figure out how to get there.
A solution containing 0.0837 M caffeine and 0.0666 M niacin as the internal
standard gave R = 423 and R = 347. To analyze a caffeine tablet, 20.0 mL caff niacin
0.146 M niacin and 20.0 mL of caffeine tablet solution were mixed and diluted to
50.0 mL in a VF. Instrument gave R = 553 and R = 582. What is the caff niacin
concentration of caffeine in the 20.0 mL caffeine solution?
Explanation / Answer
concentration=stock*amount of volume added/volume make up