posted by Un on .
o prepare a 200 mL of aqueous stock solution X, you transferred 50 mL of a known concentration solution into a 200 mL volumetric flask. If you realize that the volumetric flask was contaminated with water droplets after you cleanly transferred the known concentration solution. The 200 mL solution X will have a?
(higher, lower or same) concentration than(as) you originally calculated.
Let's see. We transfer 50 mL of a known concn into a 200 mL volumetric flask. The 200 mL flask already contained some water in it. Then you added water to fill to the mark in the 200 mL volumetric flask. What difference does it make how much water was in the flask (at least as long as the amount of water was less than 200-50)? Extra water was just extra water. What matters is that the final volume was 200 you used 50 mL of stock solution to start, so you have diluted it 50 to 200.