What type of substance is $NH_{3}$?

What is the concentration of $[OH^-]$ in distilled water at $298 \; K$?

According to the Arrhenius theory,which ion is produced when a base ionizes in water?

Crystals of a substance changed their colour on heating in a closed test tube but regained it after sometime when they were allowed to cool down. Name the substance and write its formula and explain the phenomenon involved.

What happens to the $pH$ of a basic aqueous solution if the concentration of $[OH^-]$ ions increases?

Which of the following contains oxalic acid?