How Strong Are Acid or Base Solutions?

You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution respectively. If you are given only red litmus paper, how will you identify the contents of each test tube? 

Do basic solutions also have ${\mathrm{H}}^{+}\left(\mathrm{aq}\right)$ ions? If yes, then why are these basic?

What effect does the concentration of ${\mathrm{H}}^{+}\left(\mathrm{aq}\right)$ ions have on the nature of the solution?

You have two solutions, A and B. The pH of solution A is 6 and pH of solution B is 8.

Which solution has more hydrogen ion concentration? Which of this is acidic and which one is basic?

How is the concentration of hydroxide ions ${\text{OH}}^{\text{-}}$ affected when excess base is dissolved in a solution of sodium hydroxide?

How is the concentration of hydronium ions ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$ affected when a solution of an acid is diluted?

Why does dry $\mathrm{HCl}$ gas not change the colour of the dry litmus paper?

Why do ${\text{HCl, HNO}}_{\text{3}}\text{,}$ etc., show acidic characters in aqueous solutions while solutions of compounds like higher alcohols and glucose do not show acidic character?

A solution turns red litmus blue, its pH is likely to be:

Fresh milk has a pH of 6. How do you think the pH will change as it turns into curd? Explain your answer.

Five solutions A, B, C, D, and E, when tested with universal indicator, showed pH as $4, \mathrm{1,} \mathrm{11,} 7$ and $\mathrm{}9,$ respectively. Which solution is
(i) Neutral?
(ii) Strongly alkaline?
(iii) Strongly acidic?
(iv) Weakly acidic?
(v) Weakly alkaline?
Arrange the pH in increasing order of hydrogen-ion concentration.

Why do acids not show acidic behaviour in the absence of water?

Which one of the following types of medicine is used for treating indigestion?

$10$ml of a solution of $\mathrm{NaOH}$ is found to be completely neutralized by $8$ ml of a given solution of $\mathrm{HCl}$. If we take $20$ ml of the same solution of $\mathrm{NaOH}$, the amount of $\mathrm{HCl}$ solution (the same solution as before) required to neutralize it will be