Dilution Problems

If a solution is diluted, the volume is increased and the concentration of solute decreased, but the number of moles of solute remains constant. Since C = n/V, n = CV, and we have a simple  relation between the original molar concentration and volume and the final concentration and volume after dilution:

The subscripts here refer to the particular state of teh system, 1 to the initial state, and 2 to the final state

Example 3

Suppose that 25 mL of the 1.83 M NaCl solution is diluted to 100 mL. What is the final molar concentration of NaCl?