The colour of $pH$ paper strip at the $pH$ values of $1, 7,$ and $14$ will be:

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

At what $pH$ is rain water said to be acidic?

Answer the following:
$(i)$ Why is Plaster of Paris written as $CaSO_{4} \cdot 1/2 H_{2}O$? How is it possible to have half a water molecule attached to $CaSO_{4}$?
$(ii)$ Why is sodium hydrogen carbonate an essential ingredient in antacids?
$(iii)$ When electricity is passed through an aqueous solution of sodium chloride,three products are obtained. Why is the process called chlor-alkali?

What is the effect of an acid on litmus paper?

Which of the following is not a strong acid?