Be sure to answer all parts. what are e and ag of a redox reaction at 25°c for which n=1 and k= 7.0 x 104? ag° = oj

Answer :

The standard Gibbs free energy is, -27640.414 J

The standard cell potential is, 0.29 V

Explanation :

First we have to calculate the .

Formula used :

where,

= standard Gibbs free energy = ?

R = gas constant = 8.314 J/K.mole

n = number of moles = 1 mole

T = temperature =

k = equilibrium constant =

Now put all the given values in this formula, we get:

The standard Gibbs free energy is, -27640.414 J

Now we have to calculate the standard cell potential.

Formula used :

where,

= Gibbs free energy = -27640.414 J

n = number of electrons = 1

F = Faraday constant = 96500 C/mole

= standard e.m.f of cell = ?

Now put all the given values in this formula, we get the Gibbs free energy.

The standard cell potential is, 0.29 V

part 1: the half-life of the element is 22 years.

part 2: it will take 132.02 year for the sample to decay from 308.0 g to 4.8125 g.

explanation:

part 1: there are two ways to determine the half life time.

first way: the half life time can be determined directly from its definition as it is the time required for the sample to decay to its half concentration.

from the data the initial concentration was 45.0 g and decayed to its half value (22.5 g) in 22.0 years.

second way: the radio active decay is considered first order reaction so we can use the laws of first order reactions.

k = (1/t) ln (a/a-x), where k is the rate constant of the reaction,

t is the time of the reaction

a is the initial concentration of the reactant

a-x is the remaining concentration at time (t)

a = 45.0 g the initial concentration at t = 0 year.

at t = 22 year, a-x = 22.5 g

then k = (1/22 year) ln (45.0 g/ 22.5 g) = 0.0315 year-1.

the half-life time (t1/2) = ln 2/ k = 0.693/ k =0.693/ 0.0315 = 22 years.

part 2:

using the same law k = (1/t) ln (a/a-x),

using the given data; a = 308.0 g and a-x = 4.8125 g and the calculated k from the part 1 (k = 0.0315 year-1)

t = (1/k) ln (a/a-x) = (1/0.0315) ln (308.0/ 4.8125) = 132.02 years

i don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.