Properties of Acids

The following are properties of acids:

1. Dilute acids have sour taste.

2. They turn moist blue litmus paper red.

3. Some acids are corrosive, however, this is not a general property.

4. Most acids are solids.

5. More reactive metals, e.g. Zn, Mg, Al and Fe react with acids to liberate hydrogen. Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)

6. Stronger and less volatile acids displace weaker and more volatile acids from their salts.

7. Acids, except very weak acids like H₂CO₃, when reacted with a trioxocarbonate(IV) liberate CO₂, which turns lime water milky. Example, 2HCl(aq) + CaCO₃(s) → CaCl₂(aq) + H₂O(l) + CO₂(g)

H₂CO₃ dissolves a trioxocarbonate(IV) to give a bicarbonate (i.e., hydrogen trioxocarbonate(IV)).

H₂CO₃(aq) + CaCO₃(s) → Ca(HCO₃)₂(aq)

8. Acids react with bases or alkalis to give salts and water.

9. Solutions of acids can conduct electricity (i.e., they are electrolyte).

10. Acids have pH values below 7.