Tag: electrochemistry

Quizzes (9) Questions (132)

Questions Related to electrochemistry

Multiple choice metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

 The standard electrode potentials ${\text{E}} _{{{\text{I}} _2}/{1^ - }}^ \circ ,{\text{E}} _{{\text{B}}{{\text{r}}^ - }/{\text{B}}{{\text{r}} _2}}^ \circ $ and ${\text{E}} _{{\text{Fe/F}}{{\text{e}}^{2 + }}}^ \circ $ are respectively $ + 0.54{\text{V,}} - 1.09{\text{V}}$ and 0.44 V. On the basis of the above data which of the following process is nonspontaneous?

  1. ${\text{B}}{{\text{r}} _2} + 2{{\text{I}}^ - }\;{\text{2B}}{{\text{r}}^ - } + {{\text{I}} _2}{\text{ }}$
  2. ${\text{Fe}} + {\text{B}}{{\text{r}} _2}\;{\text{F}}{{\text{e}}^{2 + }} + 2{\text{B}}{{\text{r}}^ - }$
  3. ${\text{Fe}} + {{\text{I}} _2}{\text{ F}}{{\text{e}}^{2 + }} + 2{{\text{I}}^ - }$
  4. ${{\text{I}} _2} + 2{\text{B}}{{\text{r}}^ - }2{{\text{I}}^ - } + {\text{B}}{{\text{r}} _2}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

the one which is having higher oxidation potential will undergo oxidation,

in D, $I^-$ is having lower reduction potential in comparison to $Br^-$, so has to undergo oxidation but in option D, it is getting oxidized.
hence, it is a nonspontaneous reaction.

Multiple choice metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

An alkali which dissociates partially on passage of an electric current is:

  1. sodium hydroxide

  2. nickel metal

  3. ammonium hydroxide

  4. copper
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

We have,

Sodium chloride is an ionic compound which is already present in the ionic form and completely dissociated on the passage of electric current,
Nickel and copper metal have higher reduction potential so, reduction takes place on passage of electric current,
ammonium hydroxide is a weak base it is partially dissociated on the passage of electric current.