Question

How many moles of NaOH are in 10.0 mL of a 3.00 M solution?

Answer 1

Hint: The molarity is the number of moles of solute dissolved in one liter of solution. The molarity is calculated by dividing the number of moles by the volume of solution. The unit of molarity is mol per liter or mol/L. It is represented by “M''.

Complete step by step answer:
Given,
Volume of the solution is 10.0 mL.
The molarity of the solution is 3.00 M.
The molarity is defined as the concentration of the solution where the number of moles of solute is dissolved in one liter of solution. When one mole of solute is dissolved in one liter of solution one molar solution is formed. The molarity also represents a molar solution. The molarity is represented in terms of moles per liter or mol/L. The molarity is denoted by “M”.
In this question, volume of solution and molarity is given, so the formula of molarity is used to calculate the moles of the solute.
The formula of molarity is shown below.
$M = \dfrac{n}{V}$
Where,
M is the molarity
n is the number of moles
V is the volume
To calculate the moles of solute, substitute the values of molarity and volume in the given formula.
$\Rightarrow 3.00M = \dfrac{n}{{0.01L}}$
$\Rightarrow n = 3.00M \times 0.01L$
$\Rightarrow n = 0.03mol$
Therefore, the 0.03 moles of NaOH are present in 10.0 mL of a 3.00 M solution.

Note:
Make sure to convert the volume given in milliliter into liters as the molarity is calculated in terms of liters. 1 mL is equal to 0.001 L so 10 mL is equal to 0.01 L.