To find the number of moles of NaOH present in 30.0 mL of 0.140 M NaOH, we can use the formula:
moles of solute = concentration x volume
where "solute" refers to the substance of interest (in this case, NaOH), "concentration" is the molarity of the solution, and "volume" is the volume of the solution in liters.
First, we need to convert the volume of the solution from milliliters to liters:
30.0 mL = 30.0/1000 = 0.030 L
Next, we can substitute the given values into the formula:
moles of NaOH = 0.140 mol/L x 0.030 L = 0.0042 moles
Therefore, there are 0.0042 moles of NaOH present in 30.0 mL of 0.140 M NaOH.