Julie has been asked to measure the concentration of a

Last updated: 7/31/2022

Julie has been asked to measure the concentration of a sample solution using a spectrophotometer. After a first attempt, she realizes that, to make the measurement, she must first dilute the sample solution. Julie transfers 2.0 mL of the sample to a 250 mL volumetric flask and fills the rest of the flask with water to the 250 mL line. She then uses the spectrophotometer to measure the concentration of the dilute solution as 7.9 x 10-5 M. What is the concentration of the starting sample solution?