How is the molar conductivity of a weak electrolyte at infinite d… - Vidyadip

Question

How is the molar conductivity of a weak electrolyte at infinite dilution determined?

✓

Answer

The value of limiting molar conductivity of weak electrolytes is not obtained from the graph between $\Lambda_{ m }$ and $C ^{\frac{1}{2}}$, hence it can be calculated as follows :
For example :
$C H _3 C O O H$ (Acetic acid): To determine this, the limiting molar conductivities of $CH _3 COONa , HCl$ and NaCl are used which are already known, because all of them are strong electrolytes.
Hence, $\Lambda_{ m }^{\circ}\left( CH _3 COOH \right)=\lambda_{\left( CH _3 COO ^{-}\right)}^{\circ}+\lambda_{\left( H ^{+}\right)}^{\circ}$
Acetate ion $\left( CH _3 COO ^{-}\right)$is indicated as $Ac ^{-}$.
Therefore, from $NaCl , HCl$ and $CH _3 COONa$
$
\begin{aligned}
\Lambda_{m(NaAc)}^{\circ} & =\lambda_{Ac^{+}}^{\circ}+\lambda_{Na^{+}}^{\circ} \\
\Lambda_{m(HCl)}^{\circ} & =\lambda_{H^{+}}^{\circ}+\lambda_{Cl^{-}}^{\circ} \\
\text { and } \Lambda_{m(NaCl)}^{\circ} & =\lambda_{Na^{+}}^{\circ}+\lambda_{Cl^{-}}^{\circ}
\end{aligned}
$
$\begin{aligned} \Lambda_{ m \left( CH H _3 COOH \right)}^{\circ} & =\Lambda_{ m ( HCl )}^{\circ}+\Lambda_{ m ( NaAc )}^{\circ}-\Lambda_{ m ( NaCl )}^{\circ} \\ \Lambda_{ m ( HAc )}^{\circ} & =\lambda_{ H ^{+}}^{\circ}+\lambda_{ Cl ^{-}}^{\circ}+\lambda_{ Na ^{+}}^{\circ}+\lambda_{ Ac ^{-}}^{\circ}-\lambda_{ Na ^{+}}^{\circ}-\lambda_{ Cl ^{-}}^{\circ} \\ \Lambda_{ m ( HAc )}^{\circ} & =\lambda_{\left( Ac ^{-}\right)}^{\circ}+\lambda_{ H ^{+}}^{\circ} \\ \text { or } \quad \Lambda_{ m ( HAc )}^{\circ} & =\lambda_{\left( CH _3 COO ^{-}\right)}^{\circ}+\lambda_{ H ^{+}}^{\circ}\end{aligned}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "3 Marks Question" from Electrochemistry→Electrochemistry — all question types→Chemistry STD 12 Science question papers→Bihar Board STD 12 Science question papers→Bihar Board question paper generator→

Similar questions

The emf of a cell corresponding to the reaction.
$\text{Zn(s)}+2\text{H}^+(\text{aq})\xrightarrow{ \ \ \ \ \ }\text{Zn}^{2+}(0.1\text{M})+\text{H}_2(\text{g 1 atm} )$ is 0.28 volt at 25°C.
Write the half-cell reactions and calculate the pH of the solution at the hydrogen electrode.
$\text{E}^{\circ}_{\text{Zn}^{2+}/\text{Zn}}=-0.76\text{V},\text{E}^{\circ}_{\text{H}^+/\text{H}_2}=0\text{V}$

Give the required equation for following conversions:
(i) Acetophenone to Benzoic acid
(ii) Propionic acid to Acetic acid.

A first order reaction is 50% completed in 40 minutes at 300K and in 20 minutes at 320K. Calculate the activation energy of the reaction.
$\big(\text{Given}:\log2=0.3010,\log4=0.6021,\text{R}=8.314\ \text{JK}^{-1}\text{mol}^{-1}\big)$

The following data were obtained during the first order thermal decomposition of SO₂Cl₂ at a constant volume:
SO₂Cl₂(g)$\rightarrow$SO₂(g) + Cl₂(g)

Experiment	Time/s^-1	Total pressure/atm
1 2	0 100	0.4 0.7

Calculate the rate constant.
(Given: log4 = 0.6021, log2 = 0.3010)

Write chemical reactions to show that open structure of D-glucose contains the following:

Straight chain.
Five alcohol groups.
Aldehyde as carbonyl group.

What is meant by crystal field splitting energy? On the basis of crystal field theory, write the electronic configuration of d⁴ in terms of t_2g and e_gin an octahedral field when

Δ₀>P
Δ₀<P

Explain boiling point of alkyl halides.

Neeta was experimenting in the lab to study the chemical reactivity of alcohols. She carried out a dehydration reaction of propanol at 140°C to 180°C. Different products were obtained at these two temperatures.
a. Identify the major product formed at 140°C and the substitution mechanism followed in this case.
b. Identify the major product formed at 180°C and the substitution mechanism followed in this case.

Aqueous copper sulphate solution (blue in colour) gives :
(i) a green precipitate with aqueous potassium fluoride and
(ii) a bright green solution with aqueous potassium chloride. Explain these experimental results.

The monoamino monocarboxylic acids have two pK_a values.