Define the following:
(i) Cell potential
(ii) Fuel Cell
Define the following:
(i) Cell potential
(ii) Fuel Cell
Show Hint
Solution and Explanation
(i) Cell potential, also known as the electrode potential or electromotive force (EMF), is the difference in electric potential between two electrodes in a galvanic or electrochemical cell. It is a measure of the ability of a cell to drive an electrochemical reaction and is usually measured in volts (V). The greater the cell potential, the greater the ability of the cell to perform work. The standard cell potential is calculated under standard conditions, typically 25°C, 1 M concentration for solutions, and 1 atm pressure for gases.
(ii) Fuel cell
A fuel cell is an electrochemical device that converts the chemical energy of a fuel (usually hydrogen) and an oxidant (such as oxygen) into electrical energy. This conversion occurs through a redox reaction at the electrodes. The fuel cell operates continuously as long as the fuel and oxidant are supplied, making it a clean and efficient source of power. Common examples include hydrogen fuel cells used in electric vehicles and other energy applications.
Top CBSE CLASS XII Chemistry Questions
- ${AgNO_3}$ does not decompose where :
- Azeotropic mixture of water and HCl boils at 381.5 K. By distilling the mixture it is possible to obtain
Write IUPAC names of the following compounds and classify them into primary, secondary and tertiary amines.
(i) (CH3 )2CHNH2 (ii) CH3 (CH2 )2NH2 (iii) CH3NHCH(CH3 )2
(iv) (CH3 )3CNH2 (v) C6H5NHCH3 (vi) (CH3CH2 )2NCH3 (vii) m–BrC6H4NH2
Give one chemical test to distinguish between the following pairs of compounds.
(i) Methylamine and dimethylamine
(ii) Secondary and tertiary amines
(iii) Ethylamine and aniline
(iv) Aniline and benzylamine
(v) Aniline and N-methylanilineAccount for the following:
(i) pKb of aniline is more than that of methylamine.
(ii) Ethylamine is soluble in water whereas aniline is not.
(iii) Methylamine in water reacts with ferric chloride to precipitate hydrated ferric oxide.
(iv) Although amino group is o– and p– directing in aromatic electrophilic substitution reactions, aniline on nitration gives a substantial amount of m-nitroaniline.
(v) Aniline does not undergo Friedel-Crafts reaction.
(vi) Diazonium salts of aromatic amines are more stable than those of aliphatic amines. (vii) Gabriel phthalimide synthesis is preferred for synthesising primary amines.
Top CBSE CLASS XII Electrochemistry Questions
- Define conductivity and molar conductivity for the solution of an electrolyte. Discuss their variation with concentration.
- Arrange the following metals in the order in which they displace each other from the solution of their salts.
Al, Cu, Fe, Mg and Zn - Given the standard electrode potentials,
K+/K = -2.93V, Ag+/Ag = 0.80V,
Hg2+/Hg = 0.79V
Mg2+/Mg = -2.37 V, Cr3+/Cr = - 0.74V
Arrange these metals in their increasing order of reducing power. - Depict the galvanic cell in which the reaction Zn(s) + 2Ag+(aq) → Zn2+(aq) + 2Ag(s) takes place. Further show:
(i) Which of the electrode is negatively charged?
(ii) The carriers of the current in the cell.
(iii) Individual reaction at each electrode. - Calculate the standard cell potentials of galvanic cells in which the following reactions take place:
(i) \(2Cr_{(S)}+3Cd^{2+}_{(aq)} \rightarrow 2Cr^{3+}_{(aq)}+3Cd\)
(ii) \(Fe^{2+}_{(aq)}+Ag^+_{(aq)} \rightarrow Fe^{3+}_{(Aq)}+Ag(s)\)
Calculate the \(\triangle_rG^\ominus\) and equilibrium constant of the reactions.
Top CBSE CLASS XII Questions
- 2, b, c are in A.P. and the range of determinant $\begin{vmatrix}1&1&1\\ 2&b&c\\ 4&b^{2}&c^{2}\end{vmatrix}$ is [2, 16]. Then find range of c is
- A boy of mass 50 kg is standing at one end of a, boat of length 9 m and mass 400 kg. He runs to the other, end. The distance through which the centre of mass of the boat boy system moves is
- A capillary tube of radius r is dipped inside a large vessel of water. The mass of water raised above water level is M. If the radius of capillary is doubled, the mass of water inside capillary will be
- A circular disc is rotating about its own axis. An external opposing torque 0.02 Nm is applied on the disc by which it comes rest in 5 seconds. The initial angular momentum of disc is
- A circular disc is rotating about its own axis at uniform angular velocity \(\omega.\) The disc is subjected to uniform angular retardation by which its angular velocity is decreased to \(\frac {\omega}{2}\) during 120 rotations. The number of rotations further made by it before coming to rest is