Electrochemistry and Current Electricity

Yes, battery is a combination of cells connected together. The positive terminal of one cell is connected to the negative terminal of the next cell. The minimum number of cells needed to make a battery is 2.

This statement is correct. If a salt bridge is removed between the two half cells, the voltage will drop to zero.

The cell reaction is Fe²⁺ (aq) + Ag⁺ (aq) → Fe³⁺ (aq) + Ag (s)E^o cell = E^o Fe²⁺ → Fe³⁺ + E Ag⁺ → Ag (s)E^o cell = (- 671) + (0.699)E^o cell = + 0.028 vE^o cell = 0.059/n log (Fe³⁺ x Ag)/(Fe²⁺ x [Ag⁺]) Now E^o cell = 0.028 vn = 1, [Fe³⁺] = [ Fe²⁺] = 1 M, [Ag⁺] = ? 0.028 = 0.059/1 log (1 x 1)/(1 x [Ag + ]) 0.028/0.059 = log 1/([Ag⁺])log 1/([Ag⁺]) = 0.4745log 1/([Ag⁺]) = 10^0.4745 = 2.98 [Ag+] = 1/2.98 = 0.335 M.

Standard cell potential, E^o_cell = E^o_cathode - E^o_anode = +0.43 – (-0.67) v = +1.10 v

Both are false. In electroplating the article to be electroplated serves as anode and electrolysis involves oxidation and reduction respectively at anode and cathode.

To measure transmembrane potential (voltage difference across a membrane), you need two electrodes: one inside the cell and one outside in the extracellular fluid. A single electrode cannot measure a voltage difference - it requires two reference points.

The resting membrane potential in neurons typically falls between -40 and -90 mV, with -70 mV being the most commonly cited value. This negative charge exists because the inside of the cell is more negatively charged than the outside due to ion concentration gradients.

For typical excitable cells like neurons, the threshold potential required to trigger an action potential is approximately -55 to -60 mV.

Standard electrode potential values for two half cell reactions suggest that aluminium has high tendency to make Al³⁺(aq) ions, whereas Tl³⁺ is not only unstable in solution but is a powerful oxidising agent also. Thus, Tl⁺ is more stable in solution than Tl³⁺. Aluminium being able to form Al³⁺ ions easily, is more electropositive than thallium.

One mole of electrons is equal to 1 faraday.

The blend method of electrolysis combines high frequency (thermolysis) and galvanic (electrolysis) currents. This dual action provides both heat and chemical destruction to the hair follicle.

Current density is defined as the amount of current per unit area. Therefore, the surface area of the electrode directly influences how concentrated the current is at the point of contact.

In galvanic electrolysis, the negative pole (cathode) is responsible for the chemical reaction that creates sodium hydroxide. The positive pole (anode) produces hydrochloric acid.