At 27°C, the degree of dissociation of HA (weak acid) in 0.5 M of its solution is 1%. The concentrations of H\(_3\)O\(^+\), A\(^-\), and HA at equilibrium (in mol L\(^{-1}\)) are respectively:
Show Hint
- \( 0.005, 0.005, 0.495 \)
- \( 0.05, 0.05, 0.45 \)
- \( 0.01, 0.01, 0.49 \)
- \( 0.005, 0.495, 0.005 \)
The Correct Option is A
Solution and Explanation
Step 1: Define Dissociation Equation For a weak acid HA dissociating in water: \[ HA \rightleftharpoons H_3O^+ + A^- \]
Step 2: Compute Concentrations Given initial concentration: \[ [HA] = 0.5 \text{ M}, \quad \alpha = 1\% = 0.01 \] \[ \text{Dissociated amount} = 0.5 \times 0.01 = 0.005 \text{ M} \] \[ [H_3O^+] = [A^-] = 0.005 \text{ M}, \quad [HA] = 0.5 - 0.005 = 0.495 \text{ M} \]
Top AP EAMCET Chemistry Questions
- If the $pK_a$ of acetic acid and $pK_b$ of dimethylamine are $4.76$ and $3.26$ respectively, the pH of dimethyl ammonium acetate solution is
- In the first order thermal decomposition of $C _{2} H _{5} I (g) \longrightarrow C _{2} H _{4}(g)+ HI (g)$, the reactant in the beginning exerts a pressure of $2$ bar in a closed vessel at $600 \,K$. If the partial pressure of the reactant is $0.1$ bar after $1000$ minutes at the same temperature the rate constant in $\min ^{-1}$ is $(\log 2=0.3010)$
- Isopropyl benzene on aerial oxidation followed by acid hydrolysis of the resulting compound yields
- Sodium nitrite is reacted with $H_2SO_4$ to form $NaHSO_4, HNO_3$, water and $X$. Gold is dissolved in aqua-regia to form water, $AuCl^{-}_4$ and $Y. X$ and $Y$ are respectively
- The average translational kinetic energy of a molecule in a gas becomes equal to $0.69\, eV$ at a temperature about [Boltzmann constant = $1.38 \times 10^{-23} \; J \; K^{-1}$]
Top AP EAMCET Law Of Chemical Equilibrium And Equilibrium Constant Questions
- At 300 K, for the reaction, \[ \text{A}_2 \text{B}_2(g) \rightleftharpoons \text{A}_2(g) + \text{B}_2(g) \]
\(\text{is 100 mol L}^{-1}\). \(\text{What is its } K_p \text{(in atm)} \text{at the same temperature?} \)
\(\text{(R = 0.082 L atm mol}^{-1}\) \(\text{K}^{-1}) \) - 10 g of a metal (M) reacts with oxygen to form 11.6 g of oxide. What is the equivalent weight of \( M \)?
At equilibrium for the reaction $ A_2 (g) + B_2 (g) \rightleftharpoons 2AB (g) $, the concentrations of $ A_2 $, $ B_2 $, and $ AB $ respectively are $ 1.5 \times 10^{-3} M $, $ 2.1 \times 10^{-3} M $, and $ 1.4 \times 10^{-3} M $. What will be $ K_p $ for the decomposition of $ AB $ at the same temperature?
- At temperature \( T \) (K), the equilibrium constant \( K_c \) for the reaction: \[ A_2(g) \rightleftharpoons B_2(g) \] is 99.0. Two moles of \( A_2(g) \) were heated in a 1L closed flask to reach equilibrium. What are the equilibrium concentrations (in \( mol \ L^{-1} \)) of \( A_2(g) \) and \( B_2(g) \)?
At \( 27^\circ C \), the degree of dissociation of weak acid (HA) in its 0.5M aqueous solution is 1%. Its \( K_a \) value is approximately:
Top AP EAMCET Questions
- If $\int \cos x . \cos 2x . \cos 5x dx = A \; \sin 2x + B \sin 4x + C \sin 6x + D \sin 8x + k $ (where $k$ is the arbitrary constant of integration), then $\frac{1}{B} + \frac{1}{C} = $
- If $k$ is one of the roots of the equation $x^2 - 25x + 24 = 0 $ such that $A = \begin{bmatrix}1&2&1\\ 3&2&3\\ 1&1&k\end{bmatrix} $ is a non-singular matrix, then $A^{-1}$ =
- If only $\frac{1}{51}^{th}$ ot the main current is to be passed through a galvanometer then the shunt required is $R_1$ and if only $\frac{1}{11}^{th}$ of the main voltage is to be developed across the galvanometer, then the resistance required is $R_2$. Then $\frac{R_2}{R_1} =$
- If $p$ and $q$ are respectively the global maximum and global minimum of the function $f(x) = x^2 e^{2x}$ on the interval $[-2, 2]$ , then $pe^{-4} + qe^4 = $
- If $\displaystyle\sum^n_{k - 1} \tan^{-1} \left( \frac{1}{k^2 + k + 1} \right) = \tan^{-1} (\theta) $ , then $\theta$ =