Question

Arrange the following substances in order of increasing acidity:
(a) Household ammonia, pH = 11.4
(b) Vinegar , $[{{H}_{3}}{{O}^{+}}]=(2.5)({{10}^{-10}})M$
(c) Grape juice, $[O{{H}^{-}}]=(1.0)({{10}^{-10}})M$
(d) Sulfuric acid, pOH = 13.6
(e) Eggs, pH = 7.8
(f) Rain water, $[{{H}_{3}}{{O}^{+}}]=(2.0)({{10}^{-6}})M$
(i). (a), (e), (f), (c), (b), (d)
(ii). (e), (a), (f), (c), (b), (d)
(iii). (b), (c), (f), (e), (a), (d)
(iv). (d), (f), (e), (c), (b), (a)

Answer 1

Hint: pH is the power of hydrogen. pH is a scale which is used to specify the acidity of the basicity of an aqueous solution. If a solution is acidic then the value of pH will be low and if the solution is basic then the value of pH will be high.

Complete step by step solution:
pOH is the measure of the OH ions concentration in a solution. It is used to express the alkalinity of a solution. Aqueous solutions having the value of pOH greater than 7 are acidic in nature whereas aqueous solutions having the value of pOH less than 7 are alkaline in nature. The hydronium ion concentration can be calculated by reversing the mathematical operation to find the pH. Hydronium ion concentration will be equal to $10^{-pH}$. Form the above paragraph we can say that least acidic substance will be household ammonia because it has the highest pH , then eggs, then rain water, grape juice, vinegar and the most acidic will be sulfuric acid having pOH = 7.8

Hence the correct answer is option (i)

Additional information:
The concept and the formula of pH was given by Sorenson. We can find the pH of a solution by finding the concentration of hydrogen ions present in the solution, similarly the concentration of hydrogen ions can be found by the pH of the solution.

Note: High pH means that the solution is basic in nature whereas high pOH means that the solution is acidic in nature. The sum of pH and pOH is equal to 14. While calculating the pH it is important to remember the basic rules for calculation using logarithm.