1. Imagine that you work at a company that prepares chemical solutions. You are asked to label a solution to sell to different customers. One customer is a hospital, another is a chemistry lab at a university, and a third is a physics lab at a university. You added 900 kg of NaCl in a 100-liter container and filled it with water to a volume of 100 liters. Assume standard (STP) conditions.

Question

1.	Imagine that you work at a company that prepares chemical solutions. You are asked to label a solution to sell to different customers. One customer is a hospital, another is a chemistry lab at a university, and a third is a physics lab at a university. You added 900 kg of NaCl in a 100-liter container and filled it with water to a volume of 100 liters. Assume standard (STP) conditions.

Determine the following:

•	Mass percentage of the solution for the customer in the hospital
•	Molarity for the customer in the chemistry lab
•	Molality for the customer of the physics lab

DrBob222 · Answer

a.
%w/w = (grams solute/g solution)*100
% = [900,000/(100,000+900,000)] x 100 = ?

b.
M = mols solution/L solution.
mols solute = grams/molar mass = ?
L solution = 100
Solve

c.
m = mols solution/kg solvent
m = mols solute same as for part b.
kg solvent you don't know and there is no way to calculate it. You don't know how much water was added to the 100 liter flask; you know only that enough water was added to make 100 L along with the 900 kg NaCl. What to do? Put a note in the sample sent to the physics lab to take it to the chemistry lab and have it analyzed.