Which one of the following gives the highest amount of hydrogen ions (H⁺) ?
Sodium hydroxide solution
Milk of magnesia
Lemon juice
Gastric juice
Answer is Wrong!
Answer is Right!
This question was previously asked in
UPSC NDA-1 – 2018
A) Sodium hydroxide solution (NaOH) is a strong base, having a very high pH and thus a very low concentration of H⁺ ions.
B) Milk of magnesia (Mg(OH)₂) is a weak base, having a high pH but lower than NaOH, still a very low concentration of H⁺ ions compared to acids.
C) Lemon juice contains citric acid and has a pH typically between 2.0 and 2.5, indicating a significant concentration of H⁺ ions.
D) Gastric juice in the stomach contains hydrochloric acid (HCl) and has a very low pH, typically ranging from 1.5 to 3.5. This extremely low pH indicates a very high concentration of H⁺ ions, necessary for digesting proteins and killing ingested microorganisms. Comparing the typical pH values, gastric juice is the most acidic among the options, meaning it has the highest concentration of hydrogen ions.