Science, Tech, Math › Science How to Neutralize a Base With an Acid Share Flipboard Email Print Arindam Ghosh / Getty Images Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Todd Helmenstine Todd Helmenstine Todd Helmenstine is a science writer and illustrator who has taught physics and math at the college level. He holds bachelor's degrees in both physics and mathematics. Learn about our Editorial Process Updated on August 02, 2022 When an acid and a base react with each other, a neutralization reaction occurs, forming a salt and water. The water forms from the combination of the H+ ions from the acid and the OH- ions from the base. Strong acids and strong bases completely dissociate, so the reaction yields a solution with a neutral pH (pH = 7). Because of the complete dissociation of strong acids and bases, if you're given a concentration of an acid or base, you can determine the volume or quantity of the other chemical required to neutralize it. This example problem explains how to determine how much acid is needed to neutralize a known volume and concentration of a base. Key Takeaways: Acid-Base Neutralization Solving a chemistry problem where a strong acid neutralizes a strong base is straightforward because both the acid and the base completely dissociate.In contrast, neutralization involving a weak acid and/or a weak base requires that you know and use the dissociation constant.Neutralization occurs at the point where the number of moles of H+ equals the number of moles of OH-. Review of Neutralization Reaction Neutralization relies on dissociation of an acid and a base. Dissociation is where the acid or base breaks into its component ions. The ions participating in a neutralization reaction are the H+ from the acid and the OH- from the base. The general form of the reaction is: acid + base → salt + waterAH + B → A + BH As an example, when hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH), it produces table salt or sodium chloride (NaCl) and water: HCl + NaOH → NaCl + H2O Neutralization requires equal amounts of H+ and OH-. So, knowing the volume and concentration of either the acid or base lets you find the volume and concentration of its partner in the reaction. Solving an Acid-Base Neutralization Problem What volume of 0.075 M HCl is required to neutralize 100 milliliters of 0.01 M Ca(OH)2 solution? HCl is a strong acid and will dissociate completely in water to H+ and Cl-. For every mole of HCl, there will be one mole of H+. Since the concentration of HCl is 0.075 M, the concentration of H+ will be 0.075 M. Ca(OH)2 is a strong base and will dissociate completely in water to Ca2+ and OH-. For every mole of Ca(OH)2 there will be two moles of OH-. The concentration of Ca(OH)2 is 0.01 M so [OH-] will be 0.02 M. So, the solution will be neutralized when the number of moles of H+ equals the number of moles of OH-. Step 1: Calculate the number of moles of OH-. Molarity = moles/volume moles = Molarity x Volume moles OH- = 0.02 M/100 milliliters moles OH- = 0.02 M/0.1 liters moles OH- = 0.002 moles Step 2: Calculate the Volume of HCl needed Molarity = moles/volume Volume = moles/Molarity Volume = moles H+/0.075 Molarity moles H+ = moles OH- Volume = 0.002 moles/0.075 Molarity Volume = 0.0267 Liters Volume = 26.7 milliliters of HCl Performing the Calculation 26.7 milliliters of 0.075 M HCl is needed to neutralize 100 milliliters of 0.01 Molarity Ca(OH)2 solution. The most common mistake people make when performing this calculation is not accounting for the number of moles of ions produced when the acid or base dissociates. It's easy to understand: only one mole of hydrogen ions is produced when hydrochloric acid dissociates, yet also easy to forget it's not a 1:1 ratio with the number of moles of hydroxide released by calcium hydroxide (or other bases with divalent or trivalent cations). The other common mistake is a simple math error. Make sure you convert milliliters of solution to liters when you calculate the molarity of your solution! Sources Skoog, D.A; West, D.M.; Holler, J.F.; Crouch, S.R. (2004). Fundamentals of Analytical Chemistry (8th ed.). Thomson Brooks/Cole. ISBN 0-03-035523-0.Snoeyink, V.L.; Jenkins, D. (1980). Aquatic Chemistry: Chemical Equilibria and Rates in Natural Waters. New York: Wiley. ISBN 0-471-51185-4.Trummal, Aleksander; Lipping, Lauri; Kaljurand, Ivari; Koppel, Ilmar A.; Leito, Ivo (2016). "Acidity of Strong Acids in Water and Dimethyl Sulfoxide". The Journal of Physical Chemistry A. 120 (20): 3663–3669. doi:10.1021/acs.jpca.6b02253Zumdahl, Steven S. (2009). Chemical Principles (6th ed.). New York: Houghton Mifflin Company. Cite this Article Format mla apa chicago Your Citation Helmenstine, Todd. "How to Neutralize a Base With an Acid." ThoughtCo, Aug. 2, 2022, thoughtco.com/neutralizing-a-base-with-acid-609579. Helmenstine, Todd. (2022, August 2). How to Neutralize a Base With an Acid. Retrieved from https://www.thoughtco.com/neutralizing-a-base-with-acid-609579 Helmenstine, Todd. "How to Neutralize a Base With an Acid." ThoughtCo. https://www.thoughtco.com/neutralizing-a-base-with-acid-609579 (accessed December 2, 2022). copy citation Watch Now: What are the Differences Between Acids and Bases?