21.

You are watching: How many unpaired electrons does nickel have

Consider the complying with changesM(s) → M(g) ... (1)M(g) → M2+(g) + 2e- ...(2)Mg) → M+(g) + e- ...(3)M(g) → M2+(g) + e- ...(4)M(g) → M2+(g) + 2e- ...(5)The 2nd ionisation energy of M could be established from the energy values connected with

1 + 2 + 4

2 + 3 - 4

1 + 5 - 3

5 - 3


Second ionisation power is the quantity of power required come take the end an electron indigenous the monopositive cation.Thus, M(g) → M2+ (g) + 2e- ...(5)

M (g) → M+ (g) + e- ...(3)

On subtracting (3) indigenous (5), us get,

M+ → M2+ + e-


22.

If the ionisation energy and also electron affinity that an element are 275 and also 86 kcal mol-1 respectively, climate the electronegativity of the aspect on the Mulliken range is

2.8

0.0

4.0

2.6


According to Mulliken, electronegativity of one atom is typical of IE and EA (in eV)nm=IE + EA2

If IE and EA room in k cal mol-1

n=IE+EA123=275+86125=2.88


Electronic configuration for Nickel (Ni) is 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d8Therefore, digital configuration for Ni2+ is 1s2, 2s2, 2p6, 3s2, 3p6, 3d8,i.e.

*

∴Ni2+ has actually two unpaired electrons.


*
move
24.

What is the value of electron gain enthalpy of Na if IE1 of Na = 5.1 eV?

-5.1 eV

-10.2 eV

+2.55 eV

+10.2eV


25.

An f-shell containing 6 unpaired electrons deserve to exchange

6 electrons

9 electrons

12 electrons

15 electrons


*


26.

An oxide that a non-metal has the adhering to properties(i) the acts both together proton donor and proton acceptor

(ii) the reacts conveniently with straightforward and acidic oxides

(iii) it oxidies Fe at its cook point. The oxide maybe

P2O5

SiO2

H2O

CO2


The correct alternative is H2O. The is because-(i) H2O is one amphoteric oxide. Therefore it deserve to donate or accept lone pair of electrons.

(ii) It conveniently react with acids and also bases.

(iii) that oxidises Fe as vapor (i.e. at its cook point).


The bespeak of size of provided cations is Li+++and the bespeak of dimension of provided anions is I- > F-.Thus, once the cation is largest and anion is smallest, the cation come anion size ratio is maximum. Hence, cation to anion size ratio is maximum for CsF.


28.

See more: How Tall Is A 40 Story Building, How Tall Is A Storey In Feet

In borax the variety of B-O-B links and B-OH bonds present are, respectively

five and four

four and also five

three and four

five and also five


In borax, the variety of B - O - B links and B-OH bonds existing are five and also four respectively.

*


Fe2+=3d64s0⇒4unpairedelectronCu+=3d104s0⇒0unpairedelectronZn=3d104s2⇒0unpairedelectronNi3+=3d74s0⇒3unpairedelectron