How to neutralize sulfuric acid

By Jillian Jastrzembski

Chemical neutralization consists of reacting an acid and a base to form salt and water. Neutralizing strong acids, such as sulfuric acid, can greatly mitigate the safety risks of these hazardous chemicals. It can also reduce business/laboratory costs by cutting down on hazardous waste, which is expensive to dispose of.

The neutralization procedure can be dangerous if not performed correctly by a trained chemist. Sulfuric acid itself is a highly hazardous chemical and can produce a violent reaction when reacted with a neutralizing base.

In this article, we’ll explain how to safely neutralize sulfuric acid, when to neutralize sulfuric acid, and where to restock on sulfuric acid.

What is sulfuric acid?

Sulfuric acid (sometimes spelled sulphuric acid) has the chemical formula H2SO4. It is one of just seven strong acids. You will find it as a clear, odorless, colorless liquid. As a highly corrosive material, it has the ability to cause thermal burns, permanent organ damage, and even death.

Beyond its role as a common laboratory reagent, it is used in the manufacture of the following:

• Antifreeze
• Batteries
• Detergents
• Drain cleaners
• Fertilizers
• Insecticides
• Pharmaceuticals
• Pigments

Why neutralize sulfuric acid?

Neutralization of sulfuric acid may be necessary in the case of a solvent spill, or prior to disposal of expired or excess inventory. Sulfuric acid is a hazardous material, but the hazardous risks can be removed via neutralization. Neutralization is therefore an important safety measure. It can also save your business or laboratory on costs, since arranging hazardous waste pick-up can be expensive.

How to neutralize sulfuric acid

The chemical concept of neutralization is theoretically very simple. When you combine an acid and a base, they react to form water and salt. For example, if we react sulfuric acid with a base such as potassium hydroxide, the following reaction will occur:

H2SO4 (aq) + 2KOH (aq) → K2SO4 (aq) + H2O (l)

The salt in this case is potassium sulfate, and it is dissolved in water. A reaction with a different base will obviously produce the corresponding salt. There are a multitude of different bases you can choose for the reaction. Some of these include:

• Potassium hydroxide
• Sodium hydroxide
• Calcium hydroxide
• Magnesium oxide
• Ammonia
• Sodium bicarbonate (baking soda)

You will want to choose the base you have on hand, or the base that is most economically feasible. For example, sodium bicarbonate is a readily available and cheap household item, but it is probably not the most appropriate choice in a laboratory or business situation (although it will still work).

The person performing the neutralization reaction should wear the appropriate personal protective equipment, including gloves, lab coat, and splash goggles. Work in a ventilated area such as a fume hood. If the neutralization is being performed as the result of a spill, this is not always possible, in which case other safety precautions must be taken. The facility should be equipped with an eye wash and a safety shower.

To mitigate the risk of handling the sulfuric acid, you may first wish to dilute the acid. Always dilute acids by adding acid to water, and not the other way around.

When you are ready to perform the reaction, combine the acid and base in a suitable reaction vessel. The reaction mixture will fizz and bubble as an indication the reaction is occurring. You should monitor the reaction using pH paper or a pH meter, aiming for a neutral pH. Do not overshoot by adding too much base, which will result in a new kind of hazardous material.

When the reaction is complete, your final product is no longer hazardous waste. It is probably safe to pour down the drain, although you should always check with the regulations in your local jurisdiction.

How to store sulfuric acid

To avoid accumulating expired or excess inventory of sulfuric acid, always keep careful records of the reagents in your lab and adhere to proper storage conditions.

Sulfuric acid must be stored in a corrosive-resistant cabinet, in a cool and dry area, away from incompatible chemicals.

Additional accommodations may be required if you are storing sulfuric acid in bulk, or if you expect your reagents to be exposed to temperature extremes. For example, you may need to purchase special storage tanks engineered for bulk storage, with temperature control options.

Where to restock on sulfuric acid

Lab Alley has high quality sulfuric acid in stock and ready to ship as soon as you’re ready to restock. Our products are available in multiple sizes and concentrations, so that you can choose the option that best fits your needs.

Buy Sulfuric Acid Now