Phosphoric acid ionizes in three steps, with their ionization constant values \(\mathrm{K}_{\mathrm{a}_1}, \mathrm{~K}_{\mathrm{a}_2} \text { and } \mathrm{K}_{\mathrm{a}_3} \text {, }\)respectively, while \(K\) is the overall ionization constant.  Which of the following statements are true?
A. \(\log \mathrm{K}=\log \mathrm{K}_{\mathrm{a}_1}+\log \mathrm{K}_{\mathrm{a}_2}+\log \mathrm{K}_{\mathrm{a}_3}\)
B.  \(\mathrm{H}_3 \mathrm{PO}_4\) is a stronger acid than \(\mathrm{H}_2 \mathrm{PO}_4^{-}\) and \(\mathrm{HPO}_4^{2-} .\)
C. \(\mathrm{K}_{a_1} >\mathrm{~K}_{\mathrm{a}_2}>\mathrm{K}_{\mathrm{a}_3} \)
D. \(\mathrm{K}_{\mathrm{a}_1}=\frac{\mathrm{K}_{\mathrm{a}_3}+\mathrm{K}_{\mathrm{a}_2}}{2}\)
Choose the correct answer from the options given below : 
1. B, C and D only 
2. A, B and C only 
3. A and B only 
4. A and C only
Subtopic:  Ionisation Constant of Acid, Base & Salt |
 54%
From NCERT
NEET - 2025
Please attempt this question first.
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Consider the following reaction in a sealed vessel at equilibrium with concentrations of
\(\text{N}_2=3.0 \times 10^{-3} \text{M}, \text{O}_2=4.2 \times 10^{-3} \text{M}\) and
\(\text{NO}=2.8 \times 10^{-3} \text M\)
\(2 \text{NO}_{(\text{g})} \rightleftharpoons \text{N}_{2(\text{g})} +\text{O}_{2\text{(g)}}\)

If 0.1 mol L-1 of NO(g) is taken in a closed vessel, what will be the degree of dissociation (\(\alpha\)) of NO(g) at equilibrium?

1. 0.0889
2. 0.8889
3. 0.717
4. 0.00889
Subtopic:  Ionisation Constant of Acid, Base & Salt |
From NCERT
NEET - 2024
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
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NEET 2026 - Target Batch - Vital

For a weak acid HA, the percentage of dissociation is nearly 1% at equilibrium. If the concentration of acid is 0.1 mol L-1, then the correct option for its Ka at the same temperature will be:
1. \(1 \times 10^{-4}\)    
2. \(1 \times 10^{-6} \)
3. \(1 \times 10^{-5} \)
4. \(1 \times 10^{-3} \)
Subtopic:  Ionisation Constant of Acid, Base & Salt |
 68%
From NCERT
NEET - 2023
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
Hints
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital

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