Question Video: Identifying the Definition of Molarity Chemistry • 10th Grade

Which of the following is the definition of molarity? [A] Molarity (M) is the number of moles of a substance per milliliter of solution. [B] Molarity (M) is the number of moles of a substance per liter of solution. [C] Molarity (M) is the number of grams of a substance per liter of solution. [D] Molarity (M) is the number of moles of a substance per kilogram of solution. [E] Molarity (M) is the number of mole equivalents of a substance per liter of solution.

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Video Transcript

Which of the following is the definition of molarity? (A) Molarity M is the number of moles of a substance per milliliter of solution. (B) Molarity M is the number of moles of a substance per liter of solution. (C) Molarity M is the number of grams of a substance per liter of solution. (D) Molarity M is the number of moles of a substance per kilogram of solution. (E) Molarity M is the number of mole equivalents of a substance per liter of solution.

When a solution has a higher molarity, it is more concentrated. And in the case of a colored solution, we’ll have a stronger and often darker color. As the molarity decreases, the solution becomes less concentrated and will become paler in color. Let’s take a look at the following formula, which is used to calculate molarity. In this formula, M stands for molarity, 𝑛 stands for number of moles of substance, and 𝑉 is the volume of the solution in liters.

The substance dissolved in a solution is called a solute. The more moles of solute dissolved per liter of solution, the higher the molarity. The unit M in the formula therefore means moles per liter. For example, if the concentration of a solution is written as two M, it is equal to a concentration of two moles per liter.

Based on our discussion, let’s write a definition for molarity. Molarity is defined as the number of moles of a substance per liter of solution. Therefore, the correct answer is answer choice (B). Molarity M is the number of moles of a substance per liter of solution.