Molarity: A measure of the concentration of a solution, defined as the number of moles of solute per liter of solution (moles/L).
Equation:
Molarity ( = \frac{\text{moles of solute}}{\text{liters of solution}} )
Using Molarity to Solve Problems
Basic Equations:
Molarity ( = \frac{\text{moles}}{\text{liters}} )
Moles ( = \text{molarity} \times \text{liters} )
Liters ( = \frac{\text{moles}}{\text{molarity}} )
Problem-Solving Strategies
To Find Moles:
Use the equation: ( \text{moles} = \text{molarity} \times \text{liters} )
Example: For a 2.5 M solution with a volume of 500 mL (0.5 L), the moles of solute ( = 2.5 \times 0.5 = 1.25 \text{ moles} ).
To Find Volume:
Use the equation: ( \text{liters} = \frac{\text{moles}}{\text{molarity}} )
Example: For a solution made from 0.65 moles with a desired molarity of 1.8 M,
( \text{volume} = \frac{0.65}{1.8} = 0.361 \text{ liters} ) or 361 mL.
Conclusion
Interrelationship: Molarity, moles, and volume are interconnected, allowing calculation of one if the other two are known.
Useful Tool: Molarity serves as a versatile tool for quantifying solution concentration and facilitates straightforward calculations using algebra and arithmetic.