Wally has a stock solution of 2.8M NaCl. He would like a supply of 0.7 M NaCl. How many liters of water should he add to 12 liters of the stock solution.
Fiona has a solution of ammonia gas and water at room temperature. She wants to liberate ammonia gas from the solution. How could she accomplish this?
These are two questions that i don't know how to do. if you could help me do it, it would be much appreciated.
2007-02-15 04:59:07 · 1 answers · asked by Yahoo 2 in Education & Reference ➔ Homework Help
1.) Molarity = moles/L
First: Multiply the molarity of the stock solution by volume to get # of moles:
2.8 moles / L * 12 L = 33.6 moles
Second: Divide # of moles by the end molarity to get new volume:
33.6 moles / .7 moles / L = 48L new solution.
Third: Subtract the original volume from new volume:
48L - 12L = 36L of water. (solution!)
2.) The simple way is to heat it: gaseous solutes are less soluable in water as temperature rises.
2007-02-15 06:56:13 · answer #1 · answered by ³√carthagebrujah 6 · 0⤊ 0⤋