Home
Class 11
CHEMISTRY
STATEMENT-1: The dissociation constants ...

STATEMENT-1: The dissociation constants of weak diprotic acid are in the order of `K_(a_1)gtK_(a_2)`
STATEMENT-2: Removal of `H^(+)` from anion is difficult as compared to neutral molecule.

A

If both the statements are TRUE and STATEMENT-2 is the correct explation of STATEMENT-1

B

If both the statements are TRUE AND STATEMENT-2 is NOT the correct explanation of STATEMENT-1

C

If STATEMENT-1 is TRUE and STATEMETN-2 is FLASE

D

If STATEMENT-1 is FLASE and STATEMENT-2 is TRUE

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to analyze both statements regarding the dissociation constants of a weak diprotic acid and the difficulty of removing a proton from an anion compared to a neutral molecule. ### Step-by-Step Solution: 1. **Understanding Diprotic Acids**: - A diprotic acid can donate two protons (H⁺ ions). For example, let’s consider a diprotic acid represented as H₂A. - The first dissociation can be represented as: \[ \text{H}_2\text{A} \rightleftharpoons \text{HA}^- + \text{H}^+ \] The dissociation constant for this reaction is denoted as \( K_{a1} \). 2. **Second Dissociation**: - The second dissociation occurs as follows: \[ \text{HA}^- \rightleftharpoons \text{A}^{2-} + \text{H}^+ \] The dissociation constant for this reaction is denoted as \( K_{a2} \). 3. **Comparing \( K_{a1} \) and \( K_{a2} \)**: - For weak diprotic acids, the first dissociation constant \( K_{a1} \) is generally greater than the second dissociation constant \( K_{a2} \) (\( K_{a1} > K_{a2} \)). - This is because the first dissociation produces a conjugate base (HA⁻), which is more stable than the neutral acid (H₂A). The stability of the conjugate base makes it easier for the first proton to dissociate compared to the second proton. 4. **Analyzing Statement 1**: - **Statement 1**: "The dissociation constants of weak diprotic acid are in the order of \( K_{a1} > K_{a2} \)" is **true**. 5. **Understanding the Difficulty of Proton Removal**: - **Statement 2**: "Removal of \( H^+ \) from anion is difficult as compared to neutral molecule" is also true. - This is because once the first proton is removed, the resulting anion (HA⁻) is more stable, making it less likely to lose another proton compared to the neutral molecule (H₂A). 6. **Conclusion**: - Both statements are true, and Statement 2 correctly explains Statement 1. - Therefore, the answer to the question is **A**: Both statements are true, and Statement 2 is the correct explanation for Statement 1.
Doubtnut Promotions Banner Mobile Dark
|

Similar Questions

Explore conceptually related problems

Assertion :- The dissocation constant of poly basic acid are in order K_(1)gtK_(2)gtK_(3) . Reason :- The H^(+) ion furnished in first step of dissocation exert common ion effect to reduce the second dissociation and soon.

The dissociation constant of two weak acids are k_(a_(1)) & k_(a_(2)) respectively. Their relative strength is -

STATEMENT-1: Autoprotolysis constant of water increases with the increase in temperature. STATEMENT-2: When a solution of a weak monobasic acid is titrated wita a strong base, at half neutralization point pH=pK_(a)+1. STATEMENT-3: The pH of 10^(-8) m HCl is 8.

The dissociation constant of a weak acid is 1 xx 10^(-4) . In order of prepare a buffer solution with a pH =5 the [Salt]/[Acid] ratio should be

The degree of dissociation of a weak monoprotic acid of concentration 1.2xx10^(-3)"M having "K_(a)=1.0xx10^(-4 is

Statement-1: H_(2)S is weak diprotic acid. Statement-2: Salt of aq. Na_(2)S has pH greater than 7.

STATEMENT - 1 : solubility of sulphide is higher in acidic medium than pure water. STATEMENT - 2 : Aq. Solution of metal sulphides is neutral. STATEMENT - 3 : Metal sulphides are salt of strong base and weak acid.

For a polyprotic acid, H_(3)PO_(4) its three dissociation constanst K_(1),K_(2) and K_(3) are in the order

The dissociation constant of a weak acid HA and weak base BOH are 2 xx 10^(-5) and 5 xx 10^(-6) respectively. The equilibrium constant for the neutralization reaction of the two is (ignnore hydrolysis of resulting salt )

STATEMENT-1: When 0.1 M weak diprotic acid H_(2)A dissociated with its dissociation constants K_(a_1)=10^(-3) and K_(a_2)=10^(-8) , then [A^(2-)] is almost equal to 10^(-3) M STATEMENT-2: Since K_(a_2)ltltK_(a_1) for 0.1 M H_(2)A,so[A^(2-)] is negligible w.r.t. [HA^(-)]