What is the nature of the aqueous solution of lemon juice?

$(i)$ What is the $pH$ range for a base?
$(ii)$ How can the strength of a basic solution be increased?

The marble statues are often slowly corroded when kept in the open for a long time. Give a suitable reason.

What is the $pH$ value of a basic aqueous solution?

When a $pH$ paper is dipped in an aqueous solution,it turns blue. What is the approximate $pH$ value of that solution?

Give reasons for the following:
$(i)$ Why is it recommended that acid should be added to water and not water to acid?
$(ii)$ Why do compounds like alcohol and glucose not show acidic behavior even though they contain hydrogen?