Dilution: process of converting a more concentrated solution into a less concentrated solution by adding additional solvent.

Dilutions are performed when a less concentrated solution is needed, particularly when using a premade or stock solution, such as a concentrated acid.

The following equation is used to solve dilution problems:

M_{1}V_{1} = M_{2}V_{2}

Where:

M_{1} = molarity of first (stock) solution |
M_{2} = molarity of second (dilute) solution |

V_{1} = volume of first solution |
V_{2} = volume of second (dilute) solution |

Example: What is the molarity of a 200 mL solution made from 50 mL of 8M stock solution of HCl?

Given:

- M
_{1}= 8M - V
_{1}= 50mL - M
_{2}= ? - V
_{2}= 200 mL

Solve:

M_{1}V_{1} = M_{2}V_{2} |

(8M) (50mL) = (M_{2})(200mL) |

2 M = M_{2} |