Note: Problem #3 is different.

It asks "how do you prepare?" a certain volume of solution with a certain molar concentration. Even though it asks a different question, it is still a problem that converts units, therefore it is worked with dimensional analysis.

As in any dimensional analysis problem, the first step is to write down what is given in the problem. Look closely at how the given information is written to begin dimensional analysis.

3. How much NaCl is needed to prepare 250 ml of 0.5 M salt water?

The key difference in the two types of molarity problems is that one asks for a concentration and the other provides a concentration.

You must decide which type of problem you have so you can set it up correctly!

 
Molarity Calculations

Molarity Calculation Assignment #1