Question

Write the equation for calculating molarity. Why is molarity a convenient concentration unit in chemistry?

Short answer

The equation for calculating molarity is \( M = \frac{{n_{solute}}}{{V_{solution}}} \). Molarity is a convenient concentration unit in chemistry because it directly relates the amount of solute to the volume of solution, thus being helpful in many calculations, including stoichiometric reactions. Moreover, the molar concentration remains consistent through different temperatures and pressures, making it a reliable measure of concentration.

Step-by-step solution

Define Molarity

Molarity (usually denoted by M) is defined as the number of moles of solute per liter of solution. It is a way to express the concentration of a solution.

Derive the Equation

The equation for calculating molarity (M) can be derived from its definition. As molarity is the quantity of solute in moles divided by the volume of solution in liters, it can be represented as: \( M = \frac{{n_{solute}}}{{V_{solution}}} \), where:\( n_{solute} \) is the number of moles of solute and\( V_{solution} \) is the volume of solution in liters.

Explain the Convenience

Molarity is a convenient concentration unit in chemistry because it directly relates the amount of solute to the volume of solution, which is useful in various calculations including stoichiometric reactions. Also, it allows chemists to easily change the volume of a solution without changing its concentration, making dilutions simpler. Besides, regardless of temperature and pressure, the molar concentration remains consistent, unlike other concentration measures like molality.