The strength of an acid is related to the percentage of hydrogen ions that are released when the acid is added to water. A strong acid dissociates 95 percent to 100 percent of the hydrogen ions.

Watch this animation and classify HCl and HF as either strong or weak acids.

1. Which is stronger acid, HCl, or HF?

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   HCl is the stronger acid.

2. To what degree does HCl ionize (break apart)?

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   HCl breaks apart completely (100 percent).

3. To what degree does HF ionize (break apart)?

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   HF breaks apart to a limited extent (very little).

4. What happens to the amount of HCl in solution as the amount of H+ and Cl- increases?

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   As the amount of H+ and Cl- increases, the HCl in solution decreases.

Listed below are seven bases that fit the definition of a strong base. All other acids are considered weak.