Consider the following : The concentration of hydrogen ions in an aqueous solution is expressed by its 1. pH 2. pOH 3. pKa 4. pKw Which of the above is/are correct?

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Q: 49 (NDA-II/2008)
Consider the following : The concentration of hydrogen ions in an aqueous solution is expressed by its
1. pH
2. pOH
3. pKa
4. pKw
Which of the above is/are correct?

question_subject: 

Science

question_exam: 

NDA-II

stats: 

0,13,7,13,1,4,2

keywords: 

{'hydrogen ions': [0, 0, 1, 1], 'aqueous solution': [0, 0, 4, 2], 'concentration': [0, 0, 4, 7], 'ph': [3, 0, 3, 3], 'pka': [0, 0, 1, 0], 'poh': [0, 0, 1, 0]}

The correct answer is option 1, which states that the concentration of hydrogen ions in an aqueous solution is expressed by its pH.

Let`s dissect each option to understand why the correct answer is option 1.

Option 1: pH is a measure of the concentration of hydrogen ions in a solution. It is a scale that ranges from 0 to 14, with 7 being neutral, values below 7 being acidic, and values above 7 being basic. Therefore, option 1 is correct.

Option 2: pOH is a measure of the concentration of hydroxide ions (OH-) in a solution, not the concentration of hydrogen ions. Therefore, option 2 is incorrect.

Option 3: pKa is a measure of the acidity of a compound or molecule. It represents the negative logarithm of the acid dissociation constant (Ka). While pKa is related to the concentration of hydrogen ions, it is not a direct measure of it. Therefore, option 3 is incorrect.

Option 4: pKw is the negative logarithm of the water ionization constant (Kw). It represents the equilibrium constant for the reaction of water dissociating into hydrogen ions and hydroxide ions. Although it is related to the concentration of hydrogen