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Syllabus

^{–l}respectively. The number of valence electrons is:

(A) 3 (B) 5 (C) 4 (D) 2

Q.1. Which of the following is not a Dobereiner triad ?

(a) Cl, Br, I

(b) Ca, Sr, Ba

(c) Li, Na, K

(d) Fe, Co, Ni

explain electonegativity?

what is sheilding effect?

(l) Cu will precipitate out

(2) Iron will precipitate

(3) Cu and Fe will precipitate

(4) No reaction will take place

Is it boron or carbon?

Proof the diagonal relationship between Li and Mg

Be and Al

B and Si

Ionization Enthalpy is defined as the amount of energy required to remove an atom's electron (can be valence or consecutive) ..... this definition doesn't sound so complex. The definition of Electron Gain Enthalpy - it is the amount of energy required to add an electron. But, what is Electron Affinity ? One book says it is the negative of electron gain enthalpy. Then, there is some thermodynamic rule saying negative value of electron gain enthalpy indicates that energy has to be supplied and positive value indicates energy is released. My question is how can electron gain enthalpy have both negative and positive values but ionisation enthalpy doesn't have. Also please explain what the differnece between affinity and gain enthalpy is.Thanks in advance ....

(1) CO

_{2}< SiO_{2}< SnO_{2}< PbO_{2}: increasing oxidising power(2) B < C < O < N : increasing first ionisation enthalpy

(3) NH

_{3}< PH_{3}< AsH_{3}< SbH_{3}: increasing basic strength(4) HF < HCl < HBr < HI : increasing acid strength

Option(2). How?

Q16. Given

Li(g) $\to $Li

^{+}(g)$\frac{1}{2}{\mathrm{F}}_{2}\left(\mathrm{g}\right)\to \mathrm{F}\left(\mathrm{g}\right)$

F(g) + e¯$\to $F¯(g)

Li+(g) $\to $F¯(g) $\to $LiF(s)

Li (s) + $\frac{1}{2}$F2(g) $\to $Li F(s)

520

77

(Electron gain enthalpy)

–1047

–617

Based on data provided, the value of electron gain enthalpy of fluorine would be :

(1) – 300 kJ mol

^{–1}(2) – 328 kJ mol^{–1}(3) – 350 kJ mol^{–1}(4) – 228 kJ mol^{–1}a. In the sixth period, after filling of 6p orbitals, the next electron ( i.e. 57th) enters the 5d-orbital against aufbau principal and there after filling of seven 4f- orbitals starts with cerium (Z=58) and end up with lutetium (Z=71). Explain the anomalous behaviour.

Q. Which of the following represent the correct order of acidic strength?

$a.CaO{H}_{2}OCuOC{O}_{2}\phantom{\rule{0ex}{0ex}}b.{H}_{2}OCuOCaOC{O}_{2}\phantom{\rule{0ex}{0ex}}c.S{O}_{2}{P}_{2}{O}_{3}Si{O}_{2}A{l}_{2}{O}_{3}\phantom{\rule{0ex}{0ex}}d.{P}_{2}{O}_{3}S{O}_{2}Si{O}_{2}A{l}_{2}{O}_{3}$

periodic table

s d p f

Ans: option(4). How?

h. In which case compounds of Cr show maximum radius

i. K

_{2}CrO_{7}ii. CrO

_{2}Cl_{2}iii. Cr

_{2}(SO_{4})_{3}iv. CrCl

_{2}Reducing means gain of electrons, if IE will increase ; it means atom want electrons, not give, right?

So it is directly proportional?!

text notes downlod

Reverse in postivoely ions means?!

BaO and SrO

Please explain..

Explain in detail About The position of "Hydrogen" and "Helium" in Modern Periodic Table ?

Ans : option b.

How?

Q43. Which of the following formula has involved all the energy terms used to calculated $\u2206{\mathrm{H}}_{\mathrm{\u0192}}^{\xb0}\mathrm{of}{\mathrm{Na}}_{2}{\mathrm{O}}_{\left(\mathrm{s}\right)}$ ($\u2206$H

_{sb}: Sublimation energy ; LE_{1}: First ionisation energy; LE_{2}: Second ionisation energy ; B.D.E, ; Bond dissosiation energy ; E. G.E_{1}: First electron gain enthalpy ; E.G.E_{2}: Second electron gain enthalpy ; U : Lattice energy)(A) + 2$\u2206$H

_{sb}+ LE_{1}+ LE_{2}+ $\frac{\mathrm{B}.\mathrm{D}.\mathrm{E}}{2}+\mathrm{E}.\mathrm{G}.{\mathrm{E}}_{1}+\mathrm{E}.\mathrm{G}.{\mathrm{E}}_{2}+\mathrm{U}$(B) + 2$\u2206$H

_{sb}+2LE_{1}+ $\frac{\mathrm{B}.\mathrm{D}.\mathrm{E}}{2}+\mathrm{E}.\mathrm{G}.{\mathrm{E}}_{1}+\mathrm{E}.\mathrm{G}.{\mathrm{E}}_{2}+\mathrm{U}$(C) + 2$\u2206$H

_{sb}+2LE_{1}+ $+\frac{\mathrm{B}.\mathrm{D}.\mathrm{E}}{2}+2\mathrm{E}.\mathrm{G}.{\mathrm{E}}_{1}+\mathrm{U}$(D) + 2$\u2206$H

_{sb}+ LE_{1}+ $\frac{\mathrm{B}.\mathrm{D}.\mathrm{E}}{2}+\mathrm{E}.\mathrm{G}.{\mathrm{E}}_{1}+\mathrm{E}.\mathrm{G}.{\mathrm{E}}_{2}+\mathrm{U}$how we kan calculate sigma ?

And how it affects zirconium and hafnium sizes? Please.

[O, S], [C, N], [O, N], [N, P], [Cl

^{+}, F^{+}], [K^{+}, Na^{+}]Ans : 4 acidic compounds.

Show how?

Q2. Select total number of acidic compounds out of given below.

CsOH, OC(OH)

_{2}, SO_{2}(OH)_{2}, Sr(OH)_{2}, Ca(OH)_{2}, Ba(OH)_{2}, BrOH, NaOH, O_{2}NOHI believe it should be helium!?

How? Please explain each and every point.:

13. Carefully read the following four statements related to Slater's rule and identify them as True (T) or False (F).

I - Z

_{eff}value for the valence s-electron increases more rapidly, in moving left to right in a period, in 's' and 'p' block elements compared to d-block elements.II - Z

_{eff}value for the outermost s-orbital of f-block elements, becomes constant irrespective of the number of (n-2)f - electrons and this contradicts f- contraction. This fact can be said to be a drawback of Slater's rule.III -The Slater's rule does not take into account, the relative penetrating power of s and p-orbitals.

IV - In general, for the d-block elements of 3d-series, the value of Z

_{eff}increases by 0.65 unit per element.(A) TFTF (B) TFFF (C) TTTF (D) FTTF

1]glyoxal[2]BHC

Multiple match.

Ans key: (C)- S , (D)- Q,R.

How?

Ans: option (B).

How barium has higher I.E. than potassium?

Q.19. Decreasing ionization potential for K, Ca & Ba is

(A) Ba > K > Ca

(B) Ca > Ba > K

(C) K > Ba > Ca

(D) K > Ca > Ba

Please clear my doubt!