E = E° - RTlnK/nF where E° is the standard potential voltage R is the universal gas constant = 8.314 J/mol·K K is the reaction quotient n is the number of moles electrons transferred F is Faraday's constant = 96,500 C/mol e⁻
Let's determine K first. The overall reaction is:
Fe(s) + Cd²⁺(aq) --> Fe²⁺(aq) + Cd(s) Accounting for aqueous phases only, K = [products]/[reactants] = [Fe²⁺]/[Cd²⁺] = 0.10 M/1.4 M = 1/14
From the reactions written, you can see that 2 electrons were transferred. So, n = 2.
Lastly, the value for E⁰ is the sum of individual E⁰ of the reactions. E⁰ = E⁰cathode - E⁰anode Cathode reaction: Fe(s) --> 2e + Fe²⁺ (E⁰cathode = 0.44 V) Anode reaction: Cd²⁺ + 2e --> Cd(s) (E⁰anode = -0.4 V) Thus, E⁰ = 0.44 - -0.4 = 0.84 V
Substituting the values (assume T at room temperature = 298 K), E = 0.84 - (8.314)(298 K)(ln 1/14)/(2)(96,500) <em>E = 0.87 V</em>
There's less space, causing the air particles to collide with the walls of the container more frequently. Pressure is that energy caused by molecules striking a surface. Thus, compacting air molecules leads to higher pressure.
The compound that has the smallest ions with the greatest charge will have the strongest ionic bonds. On the other hand, large and minimally charged ions will form weaker bonds.
