strong acids, weak acids and their reactions

• Acids produce protons in water. Acids ionise in aqueous solutions, they produce hydrogen ions (H+)
• Acids can be strong or weak
• Strong acids (e.g. sulfuric acid, hydrochloric and nitric acids) completely ionise in water. All the acid particles dissociate to release H+ ions.


  Strong acid: HCl makes H+ and Cl-
• Weak acids(e.g. ethanoic, citric and carbonated acids) do not fully ionise in solution. Only a small proportion of acid particles dissociate to release H+ ions
• The ionisation of a weak acid is a reversable reaction, which sets up an equilibrium between the undissociated acid and the dissociated acid. Since only a few of the acid particles release H+ ions, the position of equilibrium lies well to the left.
• The pH of an acid or alkali is a measure of the concentration of H+ ions in the solution.
• For every decrease of 1 on the pH scale, the concentration of hydrogen ions increases by a factor of 10.


  So an acid that has a pH of 4 has 10 times the concentration of H+ ions of an acid that has a pH of 5.
• Acid strength tells you what proportion of the acid molecules ionise in water.

  The concentration of an acid is different. Concentration refers to how much acid there is in a certain volume of wate. Concentration is basically how watered down your acid is.
• The larger the amount of acid there is in a certain volume of liquid the more concentrated the acid is.

  So you can have dilute but strong acid, or a concentrated but weak acid.

  pH will decrease with increasing acid concentration regardless of whether it is a strong or weak acid.
• Some metal oxides and metal hydroxides dissolve in water. These soluble compounds are alkalis (react with acids)

  Even bases wont dissolve in water will still take part in neutralisation reactions with acids.

  So all metal oxides and metal hydroxides react with acids to form a salt and water.
• Metal carbonates are also bases. They will react with acids to produce salt, water and carbon dioxide.