There is more than one vial (not called that) on Poptropica islands:
Astro Knights Island
Get the replacement green fuel rod from the robot invader in the dungeon and replace the damaged one in the saucer Excalibur. Get the list of planets from the Queen, but set the saucer dials to X-56 Y-52 (the Pewter Moon).
Steamworks Island
The vial (beaker) from the Museum will be used to mix a herbicide in the lab (production zone) on the far side of the drawbridge.
You get the vial from the dungeon and put it in.
Go to the apothecary and get vial of osmium (in the yellow box) then go back to the game and he will incorrectly guess your weight.
The homophone for vial is vile.
Leigh Vial died in 1943.
Leigh Vial was born in 1909.
Laurent Vial was born in 1959.
Stéphane Vial was born in 1967.
Patrick Vial was born in 1946.
Noelle Vial died in 2003.
Noelle Vial was born in 1959.
So that you can calculate the mass of the contents alone, by subtracting the mass of the empty vial from the mass of the vial and contents.
The nurse extracted a vial of blood from the patient for testing.