No explanation is given for this question. Let's discuss the answer together.
42.
In a cell reaction, $$C{u_{\left( s \right)}} + 2Ag_{\left( {aq} \right)}^ + \to Cu_{\left( {aq} \right)}^{2 + } + 2A{g_{\left( s \right)}}$$
$$E_{{\text{cell}}}^ \circ = + 0.46\,V.$$ If the concentration of $$C{u^{2 + }}$$ ions is doubled then $$E_{{\text{cell}}}^ \circ $$ will be
No explanation is given for this question. Let's discuss the answer together.
44.
What will be the $$emf$$ for the given cell $$Pt\left| {{H_2}\left( {{P_1}} \right)\left| {{H^ + }\left( {aq} \right)} \right.} \right|\,\left| {{H_2}\left( {{P_2}} \right)} \right|Pt$$
A.
$$\frac{{RT}}{F}{\log _e}\frac{{{P_1}}}{{{P_2}}}$$
B.
$$\frac{{RT}}{{2F}}{\log _e}\frac{{{P_1}}}{{{P_2}}}$$
C.
$$\frac{{RT}}{F}{\log _e}\frac{{{P_2}}}{{{P_1}}}$$
46.
Which of the following is the cell reaction that occurs when the following half-cells are combined?
$${I_2} + 2{e^ - } \to 2{I^ - }\left( {1\,M} \right);$$ $${E^ \circ } = + 0.54\,V$$
$$B{r_2} + 2{e^ - } \to 2B{r^ - }\left( {1\,M} \right);$$ $${E^ \circ } = + 1.09\,V$$
$$A{l^{3 + }} + 3{e^ - } \to Al;$$ $${\text{Eq}}{\text{.}}\,wt.\,{\text{of}}\,Al = \frac{{27}}{3} = 9$$
$$\eqalign{
& W = Z \times I \times t \Rightarrow Z = \frac{{{\text{Eq}}.\,wt.}}{{96500}} \cr
& t = \frac{{W \times 96500}}{{Eq.\,wt. \times I}} \cr
& \,\,\, = \frac{{50 \times 96500}}{{9 \times 105}} \cr
& \,\,\, = 5105.82\,s\,\,{\text{or}}\,\,1.42\,h \cr} $$
48.
For a cell reaction involving a two-electron change, the standard e.m.f. of the cell is found to be $$0.295\,V$$ at $${25^ \circ }C.$$ The equilibrium constant of the reaction at $${25^ \circ }C$$ will be
The equilibrium constant is related to the standard emf of cell by the expression
$$\eqalign{
& \log K = {E^ \circ }_{cell} \times \frac{n}{{0.059}} = 0.295 \times \frac{2}{{0.059}} \cr
& \log K = \frac{{590}}{{59}} = 10\,\,{\text{or}}\,K = 1 \times {10^{10}} \cr} $$
49.
In the electrolytic cell, flow of electrons is from
NOTE : In an electrolytic cell, electrons do not flow themselves. It is the migration of ions towards oppositely charged electrodes that indirectly constitutes the flow of electrons from cathode to anode through internal supply.
50.
When water is added to an aqueous solution of an electrolyte, what is the change in specific conductivity of the electrolyte?
A.
Conductivity decreases
B.
Conductivity increases
C.
Conductivity remains same
D.
Conductivity does not depend on number of ions.