What is the approximate $pH$ value for a solution,if $pH$ paper turns pink when dipped into it?

Which of the following statements is correct about an aqueous solution of an acid and of a base?
$(i)$ Higher the $pH$,stronger the acid
$(ii)$ Higher the $pH$,weaker the acid
$(iii)$ Lower the $pH$,stronger the base
$(iv)$ Lower the $pH$,weaker the base

Equal volumes of hydrochloric acid and sodium hydroxide solutions of the same concentration are mixed. The $pH$ of the resulting solution is checked with a $pH$ paper. What would be the colour obtained? (You may use the colour guide given in the figure.)

As the concentration of $[H_{3}O^{+}]$ ions increases in an acidic aqueous solution,what happens to the nature of the solution?

In a basic aqueous solution,if the concentration of $[OH^-]$ decreases,what happens to the $pOH$?

In a basic aqueous solution,if the concentration of $[OH^-]$ decreases,what happens to the $pH$?