| Example 3: Calculate the number of moles of acid added to a base, if 100 mL of 0.2 M HCl were used. Remember that M is the same as moles/L. So let's first convert mL to L. Since 1 L =1000 mL, then, (100 mL) * (1 L/ 1000 mL) = 0.1 L The mL cancel, and you're left with L. Next we want to calculate moles. Hint: volume in mL * molarity = moles Answer: 0.1 L * 0.2 M = 0.02 M HCl |