How To Make Sulfuric Acid at Home?

Sulfuric acid is a useful acid to have on hand for a variety of home chemistry projects. However, it is not easy to obtain. Fortunately, you can make it yourself.

Homemade Sulfuric Acid Materials

Actually, this method starts with diluted sulfuric acid, which you boil to make concentrated sulfuric acid. This is the safest and easiest method of making sulfuric acid at home.

• car battery acid
• glass container
• outdoor source of heat, like a grill

Battery acid, which may be purchased at an automotive supply store, is approximately 35% sulfuric acid. In many cases, this will be strong enough for your activities, but if you need concentrated sulfuric acid, all you need to do is remove the water. The resulting acid will not be as pure as reagent-grade sulfuric acid, so keep this in mind.

Safest Method

If you aren't in a hurry, you can concentrate sulfuric acid by allowing the water to evaporate naturally. This takes several days.

1. Place an open container of sulfuric acid someplace with good circulation, safe from the possibility of a spill.
2. Loosely cover the container to minimize contamination with dust and other particulates. 
3. Wait. The water will evaporate out of the solution, eventually leaving you with concentrated sulfuric acid.

Note that sulfuric acid is highly hygroscopic, so it will retain a certain amount of water. You would need to heat the liquid to drive off the remaining water.

Quickest Method

 

The fastest method to concentrate sulfuric acid is to boil the water out of the acid. This is fast, but requires extreme care. You'll want to do this outdoors so that you won't be exposed to acid fumes, using borosilicate glass (e.g., Pyrex or Kimax). There is always a risk of shattering a glass container, no matter what you are heating, so you need to be prepared for that possibility. Do not leave this project unattended!

1. Heat the battery acid in a borosilicate glass pan.

2. When the liquid level stops dropping, you will have concentrated the acid as much as you can. At this point, the steam will be replaced by white vapor, too. Be careful to avoid inhaling the fumes. Continue reading..