14.Which of the following exhibit maximum paramagnetic behaviour – Fe3+ or
Ni2+
. Give reason. [Hint: Iron (Z =26); Nickel (Z = 28)]

Fe^3+

Explanation:

The electron configuration for Fe^3+ is; 1s2 2s2 2p6 3s2 3p6 3d5

The electron configuration for Ni^2+ is; 1s2 2s2 2p6 3s2 3p6 3d8

Now it is pertinent to recall that the 3d sublevel has a maximum occupancy of ten electrons. These ten electrons occupy a set of five degenerate orbitals. Having said that, it is clear that Ni^2+ ion will have two unpaired electrons while Fe^3+ will have five unpaired electrons.

Let us also not forget that paramagnetism has to do with the presence of unpaired electrons. That means that maximum paramagnetism refers to the presence of maximum number of unpaired electrons.

Since Fe^3+ has the greatest number of unpaired electrons among the duo, Fe^3+ will exhibit a maximum paramagnetic behavior.

answer; i believe that the correct answer is (a) potassium(k)

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml