Acid and Alkaline are both groups of atoms bonded together and representing the smallest unit of a chemical compound that can be active in a chemical reaction. A striking difference between a change in PH sets in when both are present in aqueous solutions. Acids have a pH value of less than seven, while alkaline has a pH value higher than 7. Also, acids are known to discharge Hydrogen ions to other compounds, basically alkaline. Alkaline, on the other hand, gives out Hydroxide ions during a chemical reaction.
In addition, Acids are known to donate protons, while alkaline is protons accepting substances. Chemical compounds for most acids start with H as in cases like Nitric acid (HNO3) Carbonic acid (H2CO3) and so on except for few cases like acetic acid (CH3COOH). Alkaline, on the other hand, commonly has OH at the end. (E.g. slake lime or calcium Hydroxide: Ca(OH)2, salt: NAOH, potassium Hydroxide: KOH, etc).