José added 0.2 Liter of water to 100 mL of 1 M HCl. What is the concentration of the diluted solution? Procedure:
A calculated amount of water is added to a specific amount of starting solution (Stock Solution), or a
defined amount of stock is added to a specific amount of water.

Calculation:
1. The molarity of solution 1 (M 1 ) x the volume of solution 1 (V 1 )= the number of moles in solution 1
(M 1 V 1 = moles 1 ).
2. When water is added there are still the same number of moles present; therefore, the number of
moles in solution 1 = the number of moles in solution 2. (moles 1 = moles 2 ) and (moles 2 = M 2 V 2 ).
3. Therefore, M 1 V 1 = M 2 V 2 .
4. To calculate the correct way to make a dilution, first record the given values of concentration
and/or volume of the stock and diluted solutions. Note what is the unknown value to calculate.
5. Rearrange the equation to solve for the unknown. (For example: V 1 = M 2 V 2 /M 1 ).
6. Plug in the known values and calculate to find the unknown.