Question

Which of the following is acidic in nature?
A.Apple juice
B.Soap solution
C.Slaked lime
D.Lime

Answer 1

Hint: An acid is a chemical species (a molecule or a ion) which has the ability to donate protons or accept electrons.
-A universal indicator is a mixture or a combination of several indicators which is added to a substance to determine its pH. pH can be considered as a number that indicates the acidic or basic nature of a solution.
- pH can be measured on the pH scale from 0(highly acidic) to 14(highly basic). Higher the hydrogen ion concentration of a substance, lower is the pH value.
-For a neutral solution, pH value is 7. If the pH value is less than 7, it represents an acidic solution and if it is higher than 7, it represents a basic solution.

Complete step by step answer:
-Generally, acids are found to taste sour due to the presence of the sour hydrogen ion and bases are found to taste bitter due to the presence of the hydroxyl ions. But they can also have other tastes depending on the part of the molecule.
-Apple juice is a kind of fruit juice which is made by softening and pressing the apple into pieces using a liquid. Apple juice is acidic due to the presence of many acids. The principal acid present in apple juice is malic acid. Other acids include quinic acid and chlorogenic acid. Because of this, the pH level of apple juice varies from 3.35 to 4. Thus, option A is correct.
-A soap is formed by the saponification reaction of a weak fatty acid and a strong base. The resulting product is a mildly weak base and has a pH above 7. So, soap solution is alkaline in nature and hence, option B is wrong.
-Slaked lime is calcium hydroxide which is basic due to the presence of hydroxyl ions. So, slaked lime is not acidic in nature and hence, option c is wrong.
-Lime is calcium oxide which is also alkaline in nature. So, option D is also wrong.

Hence option A is correct.

Note:
The processing method of apple juice also affects the pH level of apple juice. The acidity of the juice affects the taste. A less acidic juice will lack freshness in taste whereas an extremely acidic juice will be sharp in taste.
Because of the low pH of apple juice, consuming apple juice can cause gastrointestinal problems like bloating and can also cause dental erosion by softening the teeth enamel.