Why do acids not show acidic behaviour in the absence of water?

Give reasons for the following : (i) Distilled water does not conduct electricity but rain water does. (ii) Acids do not show acidic behaviour in the absence of water. (iii) A solution with pH less than 7 is acidic. (iv) HCI shows acidic behaviour in aqeous solution but C_(2)H_(5)OH does not .

With Metal Oxides|All Hydrogen Containing Compounds Are Not Acids|Acids Do Not Show Acidic Behaviour In Absence Of Water|Bases|With Metal Oxides|With Non Metal Oxides

Acids do not show their acidic properties in the absence of _____

Amino acids show amphoteric behaviour. Why?