Differences Between Strong and Weak Acids

Last Updated on March 19, 2022 by QCity Editorial Stuff

Strong acids are substances that completely dissociate in water. Weak acids are acidic compounds that only partially dissociate when dissolved in an aqueous solution. The pH of strong acid solutions is less than 7, while the pH of weak acid solutions ranges from 6 to 7. This blog post will go over the properties and differences between strong and weak acids.

Acids are a class of molecules that release hydrogen ions, H+, when dissolved in water. Acids can be classified as strong or weak depending on how many protons they donate per molecule ionized. Most acids found in the kitchen and around the house are weak because they only donate one proton per molecule ionized. Strong acids, such as sulfuric acid, donate two protons per molecule ionized and have a higher pH level than their weaker counterparts due to this increased dissociation ratio. 

The most acidic substances on earth are not even naturally occurring – hydrochloric acid is produced by reacting chlorine gas with water! In some cases though, natural sources of strong acid exist – for example, concentrated nitric acid from oxidizing ammonia and nitrates in the soil.

Comparison between Strong and Weak Acids

Parameters of ComparisonStrong AcidsWeak Acids
pHless than 7  greater than 7  
CorrosiveStrong acids are corrosive and can cause burns on contact with skin or eyesWeak acids are not as strong as strong acids
StrongerStrongerLess stronger
ReactMore reactLess react
DissolveMore dissolveLess dissolve

What are Strong Acids?

Strong acids are acids that react with bases to form salts. These reactions can be very exothermic, producing large amounts of heat and may lead to the boiling point of the acid. Acids like sulfuric acid (H2SO4) or nitric acid (HNO3) are examples of strong acids. A strong base reacts readily with a weak acid according to this equation:  H+ + OH- ↔ H2O + OH- This reaction produces water and an ionized hydroxide which is also called a conjugate base. Examples of strong bases include lye (NaOH), calcium oxide, sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium carbonate, and calcium hydroxide.

Differences Between Strong and Weak Acids

What are Weak Acids?

What are weak acids? Weak acids are molecules that dissociate at low concentrations. They don’t have a strong enough affinity for the hydrogen ion, which makes them weaker than strong acids. The pH of any solution with a given concentration of acid is lower if it has more weak base ions than if it had more strong base ions. This means that solutions with higher concentrations of H3O+ will have lower pH values than solutions with only OH- present.

The most common type of weak acid is carbonic acid (H2CO3). Carbonic acid can be found in many drinks such as soda and seltzer water because dissolved CO2 gives these drinks their fizzy taste. Another example is acetic acid, which causes the sour taste in vinegar.

Differences Between Strong and Weak Acids

10 Differences Between Strong and Weak Acids

1. Strong acids have a pH of less than 7.

2. Weak acids have a pH greater than 7.

3. Strong acids are corrosive and can cause burns on contact with skin or eyes.

4. Weak acids are not as strong as strong acids, but they still can irritate if the chemical touches your skin or eyes.

5. A weak acid will react more readily with other substances in the water to form salts and bases. 

6. A weak acid is better for cleaning because it reacts easily with dirt particles and breaks them down into smaller pieces that then dissolve in water, while a strong acid may be too harsh on surfaces like marble or granite.

7. Strong acids are strong enough to react with water and produce hydrogen gas.

8. Weak acids do not react with water and produce only a small amount of hydrogen gas.

9. A stronger acid will dissolve more substances than a weaker one.

10. Acids can be classified as either mineral or organic based on their chemical composition.

Interesting Statistics or Facts of Strong Acids

1. The strongest acid is sulfuric acid, which has a pH of 0.

2. Acids can be classified as strong or weak based on the concentration and their ability to react with other substances.

3. Strong acids are corrosive and can dissolve metals such as aluminum, zinc, lead, copper, tin, iron, nickel, and silver.

4. Weak acids include hydrochloric acid (pH 1), citric acid (pH 2), and lactic acid (pH 3).

5. A buffer is any substance that resists changes in pH by absorbing excess hydrogen ions.

6. Hydrogen ions are produced when an acidic solution reacts with a basic solution.

Interesting Statistics or Facts of Weak Acids

1. Weak acids are substances that react with water to form a hydronium ion and an acid.

2. The strength of the weak acid is determined by the extent of dissociation in the solution.

3. Acetic acid, which is found in vinegar, has a pH level between 2-4.

4. Citric Acid, which is found in oranges and lemons, has a pH level between 2-3.

5. The most common type of weak acids are hydrochloric and sulfuric acids.

6. Hydrochloric Acid’s pH ranges from 1-7 while Sulfuric Acid’s ranges from 0-8.


The differences between strong and weak acids. The acidity of a solution is often described as the concentration of hydrogen ions (H+) in it, which can be measured by pH levels on a scale ranging from 0 to 14. Solutions with low concentrations are said to have high pH values or be basic, while those with higher concentrations are acidic. Strong acids tend to fall below 7 on the pH scale; these include hydrochloric acid (0) and sulfuric acid (-2). Weak acids may range anywhere from 5-6 on this same scale – they’re not particularly acidic but still capable of dissolving materials like aluminum compounds or plastics that stronger ones cannot. For example, acetic acid found in vinegar has an approximate pH value of 4-5.


Resource 01: https://www.thoughtco.com/list-of-the-strong-acids-603651
Resource 02: https://byjus.com/chemistry/weak-acid-examples/

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