Acids are those chemical substances that contribute hydrogen ions or protons when mixed in solutions. The number of protons closed by a particular acid determines the strength of the acid – whether it is a strong acid or a weak acid. To understand the strength of acids, one needs to compare their tendency to donate protons to the same base (mostly water). Strength is represented by a number called PKA.
What is a strong acid?
An acid is said to be strong if it completely decomposes or ionizes in a solution. This means that it is capable of giving the largest number of H + ions or protons when mixed in a solution. These ions are charged particles. Since a strong acid donates a greater number of ions as it breaks down, or ionizes, it means that a stronger acid is a conductor of electricity.
When an acid combines into H 2 O, a proton (H + ion) is transported to H 2 O to produce an H3O molecule + (hydronium ion) and an – ion based on which the acid to start is involved.
In a common scenario, such chemical reactions can be reversed, but in some cases, the acid removes the H + ion quite easily and the reaction looks like one way. And the acid completely decomposes.
For example, when hydrogen chloride dissolves in H 2 O to form HCl, so there is the very little reaction we can write:
At one time, there will be a hundred percent virtual reaction in which hydrogen chloride reacts with H 3 O + (hydronium ions) and Cl – ions. Here, the strong acid is hydrogen chloride.
What is a weak acid?
An acid is said to be weak if it ionizes partially or incompletely, leaving only some of its hydrogen atoms in solution. Therefore, it is less capable than a strong acid in closing the proton. Weak acids have more PKA than strong acids.
For example Ethanoic acid.
It shows a reaction with H 2 to produce H3O + O (hydronium ion) and CH3COOH (ethanoate ion), but the reverse reaction shows more success than the forward one. Molecules react quite easily to form acids and H 2 O.
At any given time, molecules of 3 COOH acids about only one percent CH show conversion to ions. All that is left is simple acetic acid (systematically ethanoic acid) molecules.
Difference between Strong Acid and Weak Acid
|Strong Acid||Weak Acid|
|A strong acid is an acid that completely ionizes in an aqueous solution. A strong acid will always loosen a proton (AH +) when dissolved in H 2 O. In other words, a strong acid is always on its toes and is quite efficient at shutting down protons.||A weak acid is partially ionized in a solution. This leaves only some of its hydrogen atoms in the solution. It is therefore less capable than a strong acid.|
|A strong acid will always show strong conductivity. Strong acids generally uphold more current than weak acids for the same voltage and concentration.||Weak acids have low conductivity. They are poor conductors and show low values for current passing|
|The reaction is faster in strong acids.||In weak acids, the rate of reaction is slow.|
|Hydrochloric acid (HCl), Nitric acid (HNO) 3), Perchloric acid (HClO) 4), Sulfuric acid (H 2 SO 4), Hydrobromic acid (HBr), Chloric acid (HClO 3).||Sulfurous acid (H 2 SO 3), acetic acid (CH) 3 CoH), phosphoric acid (H 3 PO 4), benzoic acid (C) 6 H 5 COOH), hydrofluoric acid (HF), formic acid (HCOOH), nitrous acid (HNO) 2).|
|In a strong acid, the pH is lower than it is, generally 3. A strong acid has a very high amount of H + ions (acids with a pH of 3 have 0.001 moles per liter of hydrogen ions).||A weak acid has a pH between 3 –7.|
|The value of PKA is relatively low.||The value of PKA is very high.|
|HCl (G) + H2O (L). H3O + (aq) + Cl− (AQ)||CH3COOH (l) + H2O (l) + H3O + (aq) + CH3COO− (AQ)|