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Champ Jee
Subject: Chemistry
, asked on 19/5/18
Why neon has highest electron gain enthalpy? Why not other noble gases?
I believe it should be helium!?
Answer
1
Champ Jee
Subject: Chemistry
, asked on 16/5/18
10. The number of pairs, in which EA of the second element is more than that of the first element is :
[O, S], [C, N], [O, N], [N, P], [Cl
+
, F
+
], [K
+
, Na
+
]
Answer
1
Champ Jee
Subject: Chemistry
, asked on 16/5/18
Q2.
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
NOH
Answer
1
Champ Jee
Subject: Chemistry
, asked on 16/5/18
Q43.
Ans : option b.
How?
Q43. Which of the following formula has involved all the energy terms used to calculated
∆
H
ƒ
°
of
Na
2
O
s
(
∆
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
∆
H
sb
+ LE
1
+ LE
2
+
B
.
D
.
E
2
+
E
.
G
.
E
1
+
E
.
G
.
E
2
+
U
(B) + 2
∆
H
sb
+2LE
1
+
B
.
D
.
E
2
+
E
.
G
.
E
1
+
E
.
G
.
E
2
+
U
(C) + 2
∆
H
sb
+2LE
1
+
+
B
.
D
.
E
2
+
2
E
.
G
.
E
1
+
U
(D) + 2
∆
H
sb
+ LE
1
+
B
.
D
.
E
2
+
E
.
G
.
E
1
+
E
.
G
.
E
2
+
U
Answer
1
Champ Jee
Subject: Chemistry
, asked on 15/5/18
How ionisation energy is inversely proportional to reducing property?
Reducing means gain of electrons, if IE will increase ; it means atom want electrons, not give, right?
So it is directly proportional?!
Answer
1
Champ Jee
Subject: Chemistry
, asked on 11/5/18
Qh.
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
Answer
1
Champ Jee
Subject: Chemistry
, asked on 11/5/18
Which is the most stable element? Book shows tellurium, Google shows iron and my brain shows helium.
I am confused.
Answer
1
Champ Jee
Subject: Chemistry
, asked on 10/5/18
Explain.:
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.
Answer
1
Champ Jee
Subject: Chemistry
, asked on 10/5/18
Van der Waals radius of inert gases increases or decreases along a group?
I am confused because van der Waals forces is directly prop to molecular weight so radii must decrease?!?!
Answer
1
Champ Jee
Subject: Chemistry
, asked on 6/5/18
The electronic configuration with the highest ionization enthalpy is :-
(1) [Ar] 3d
10
4s
2
4p
3
(2) [Ne] 3s
2
3p
1
(3) [Ne] 3s
2
3p
2
(4) [Ne] 3s
2
3p
3
Answer
1
Champ Jee
Subject: Chemistry
, asked on 5/5/18
Q16.
Option(2). How?
Q16. Given
Reaction
Energy Change (in kJ)
Li(s)
→
Li(g)
Li(g)
→
Li
+
(g)
1
2
F
2
g
→
F
g
F(g) + e¯
→
F¯(g)
Li+(g)
→
F¯(g)
→
LiF(s)
Li (s) +
1
2
F2(g)
→
Li F(s)
161
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
Answer
1
Champ Jee
Subject: Chemistry
, asked on 5/5/18
In which of the following arrangements, the sequence is not strictly according to the property written against it?
(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
Answer
1
Champ Jee
Subject: Chemistry
, asked on 5/5/18
How strength of oxyacids varies in period and group? What are the factors deciding it? Please explain using examples.
Tomorrow's my test!
Answer
1
Champ Jee
Subject: Chemistry
, asked on 4/5/18
Q19.
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
Answer
5
Champ Jee
Subject: Chemistry
, asked on 1/5/18
If size of Aluminium and gallium is nearly same, then why not of silicon and germanium?
Please clear my doubt!
Answer
1
1
2
3
4
5
Next
What are you looking for?
I believe it should be helium!?
[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, SO2(OH)2, Sr(OH)2, Ca(OH)2, Ba(OH)2, BrOH, NaOH, O2NOH
Ans : option b.
How?
Q43. Which of the following formula has involved all the energy terms used to calculated (Hsb: Sublimation energy ; LE1 : First ionisation energy; LE2 : Second ionisation energy ; B.D.E, ; Bond dissosiation energy ; E. G.E1: First electron gain enthalpy ; E.G.E2 : Second electron gain enthalpy ; U : Lattice energy)
(A) + 2Hsb + LE1 + LE2 +
(B) + 2Hsb +2LE1 +
(C) + 2Hsb +2LE1 +
(D) + 2Hsb + LE1 +
Reducing means gain of electrons, if IE will increase ; it means atom want electrons, not give, right?
So it is directly proportional?!
Ans: option(4). How?
h. In which case compounds of Cr show maximum radius
i. K2CrO7
ii. CrO2Cl2
iii. Cr2(SO4)3
iv. CrCl2
I am confused.
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.
I am confused because van der Waals forces is directly prop to molecular weight so radii must decrease?!?!
(1) [Ar] 3d104s2 4p3 (2) [Ne] 3s2 3p1 (3) [Ne] 3s2 3p2 (4) [Ne] 3s2 3p3
Option(2). How?
Q16. Given
Li(g) Li+(g)
F(g) + e¯F¯(g)
Li+(g) F¯(g) LiF(s)
Li (s) + F2(g) 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
(1) CO2 < SiO2 < SnO2 < PbO2 : increasing oxidising power
(2) B < C < O < N : increasing first ionisation enthalpy
(3) NH3 < PH3 < AsH3 < SbH3 : increasing basic strength
(4) HF < HCl < HBr < HI : increasing acid strength
Tomorrow's my test!
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!