# Why are limes alkaline, but lemons are acidic? They taste about the same [closed]

So, this is kinda a dumb question, but I'm curious. Both are citrus fruits and very related to each other and taste sour which corresponds to both being acidic. Why then are limes said to be alkaline, but lemons are acidic?

• Limes have calcium oxides which in water forms calcium hydroxide, which is basic due to the hydroxyl ions. Lemons have citric acid (component of vitamin C). I never tasted the former though. – Gaurang Tandon Feb 27 '18 at 15:34
• lime: pH 2.40; and lemon: pH 2.30. source – Avyansh Katiyar Feb 27 '18 at 15:35
• Doesn’t lime refer to limewater ie., $Ca(OH)_2$? – MollyCooL Feb 27 '18 at 16:12
• @avatar just to clarify that page defines pH of the citrus fruit "lime", and not of its other popular usage, which is the inorganic oxides and carbonates of calcium – Gaurang Tandon Feb 27 '18 at 16:38

$$\ce{ CaO + H2O -> Ca(OH)2 }$$ $$\ce{ Ca(OH)2 <=> Ca^2+ + 2OH-}$$