Login
Copyright

Hydroxide Ion: Definition & Formula

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Metals on the Periodic Table: Definition & Reactivity

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:01 Hydroxide Ion:…
  • 1:27 Formula for Hydroxide
  • 2:07 Hydroxide Ion Facts
  • 3:12 Lesson Summary
Add to Add to Add to

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Login or Sign up

Timeline
Autoplay
Autoplay
Create an account to start this course today
Try it free for 5 days!
Create An Account

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Elizabeth (Nikki) Wyman

Nikki has a master's degree in teaching chemistry and has taught high school chemistry, biology and astronomy.

If the name 'hydroxide' sounds toxic to you, that's good. Hydroxide is a powerful chemical with potentially dangerous properties. Learn the definition and formula of hydroxide, as well as some interesting facts about it, in this lesson.

Hydroxide Ion: Definition and Properties

It may just be the similar 'oxic' sound, but to many, 'hydroxide' sounds like a toxic compound. It you believe this, you're not exactly wrong. Hydroxide is made of hydrogen and oxygen. Chemicals containing hydroxide can be very corrosive, and sometimes very dangerous.

The hydroxide ion is a negatively charged molecule made up of one oxygen bonded to one hydrogen. When dissolved in water, the hydroxide ion is an incredibly strong base. In fact, according to the Arrhenius definition of a base, the presence of a hydroxide ion is what makes a chemical a base. A base is a chemical that has a high pH, tastes soapy, feels slippery and reacts well with acid.

Because hydroxide has a negative charge, it is often found bonded to positively charged ions in what are known as ionic compounds. An ionic compound is a chemical composed of a positively charged ion bonded to a negatively charged ion. Some ionic compounds containing hydroxide dissolve well in water, like the corrosive bases sodium hydroxide or potassium hydroxide.

Other hydroxide containing ionic compounds are fairly insoluble in water, like bright blue copper (II) hydroxide or the brown iron (II) hydroxide. While they may be toxic, these compounds don't pose as much immediate danger as sodium hydroxide or potassium hydroxide.

Formula for Hydroxide

The formula for hydroxide is OH-. In this compound, oxygen bonds with hydrogen by sharing two electrons. Hydroxide carries a negative charge because it has gained an electron. Oxygen, depicted as an O, is bonded to hydrogen, depicted as an H, and we can see where the most negative part of the compound is with the negative sign.

If you were to zoom in to the atomic level, hydroxide would not look like a couple of letters, however. Instead, you might see a particle that looks like this model, where the large red sphere is oxygen and the smaller gray hemisphere attached to the side is hydrogen.

To unlock this lesson you must be a Study.com Member.
Create your account

Register for a free trial

Are you a student or a teacher?
I am a teacher
What is your educational goal?
 Back

Unlock Your Education

See for yourself why 10 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back

Earning College Credit

Did you know… We have over 95 college courses that prepare you to earn credit by exam that is accepted by over 2,000 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it free for 5 days!
Create An Account
Support