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HCS (Haryana)Prelims2021General Studies
Question
The substances with pH less than 7 are: a) Gastric juices b) Coffee c) Apple d) Liquid in the car battery
Options
- A 1, And 2 Only
- B 1, 3 And 4 Only
- C 1, 2 and 3 Only
- D All of these
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Correct Answer
D All of these
Model Answer
pH Scale
- Introduced by Sorensen in 1909.
- It is used to express the acidity or basicity of an aqueous solution in terms of hydrogen ion concentration [H+].
- In general, pH decreases with rising temperature.
pH is
- 7 for neutral solutions.
- Greater than 7 for basic solutions.
- Less than 7 for acidic solutions.
The pH of mentioned substances are
- Gastric juice: 1.5 - 3.5.
- Coffee: 4.85 - 5.10.
- Apple juice: 3.35 - 4.
- The liquid in the car battery: 0.7.
- Hence, the pH of all substances is less than 7 which denotes them as acidic in nature.