Ground limestone can be added to soil to make it less acidic. Would you expect the pH of limestone in a water solution to be less than or greater than 7 ?

less than 7

Explanation:

If the rainwater is always acidic then its pH must be less than 7. pH is a scale which basically means negative log of [H+] or -log[H+] and the range that it covers is from 0 to 14. A substance can be acidic, basic or neutral based on the pH that it has. If the pH of a substance is less than 7 then it means the substance is acidic, if the pH of the substance is more than 7 then it means that the substance is alkaline while a pH of 7 indicates that the substance is neutral.