\(\overset { \underset { | }{ Cl } }{ \underset { \overset { | }{ Cl } }{ CH } } -{ CH }_{ 3 }\quad (A)\) 1, 1,-dichloro ethane
\(\underset { \overset { | }{ Cl } }{ { CH }_{ 2 } } -\underset { \overset { | }{ Cl } }{ { CH }_{ 2 } } \) (B) 1, 2, dichloro ethane
\(\overset { \underset { | }{ Cl } }{ \underset { \overset { | }{ Cl } }{ CH } } -{ CH }_{ 3 }\underset { aq\quad KOH }{ \longrightarrow } \left[ \overset { \underset { | }{ OH } }{ \underset { \overset { | }{ OH } }{ CH } } -{ CH }_{ 3 } \right] \underset { -{ H }_{ 2 }) }{ \longrightarrow } { CH }_{ 3 }CHO\)
(A)                                                                    (C)
1, 1, dichloro ethane                                      Acetaldhyde
\(A \ \ \overset { \underset { | }{ Cl } }{ \underset { \overset { | }{ Cl } }{ CH } } -{ CH }_{ 3 }\)  -1,1 dichloro ethane
B  \(\underset { \overset { | }{ Cl } }{ { CH }_{ 2 } } -\underset { \overset { | }{ Cl } }{ { CH }_{ 2 } } \)-1, 2 dichloro ethane
C CH₃CHO -Acetaldehyde 
D \(\underset { \overset { | }{ OH } }{ { CH }_{ 2 } } -\underset { \overset { | }{ OH } }{ { CH }_{ 2 } } \)-Ethyleneglycol

(w) = 0.33 g
(c) = 0.397 g
\(\% I=\frac{127}{235} \times \frac{c}{w} \times 100=\frac{127}{235} \times \frac{0.235}{0.40} \times 100=31.75 \%\)

\(P_A^o\) = 10 torr, P_solution = 9 torr
W_A = 20 g  W_B = 1 g
M_A = 200 g mol^-1  M_B = ?
\({\Delta P\over P_A^o}={W_B\times M_A\over M_B\times W_A}\)
\({10-9\over 10}={1\times 200\over M_B\times 20}\)
\(M_B={200\over 20}\times 10=100\ g\ mol^{-1}\)

Given data:
[NH₃] = 1.8 x 10^-2 M
[N₂] = 1.2 x 10^-2 M
[H₂] = 3 x 10^-2 M
K_c = ?
Solution:
N_2(g) + 3H_2(g) \(\rightleftharpoons \) 2NH_3(g)
\(K_c={[NH_3]^2\over[N_2][H_2]^3}={1.8\times 10^{-2}\times 1.8\times 10^{-2}\over 1.2\times 10^{-2}\times 3\times 10^{-2}\times 3\times 10^{-2}\times 3\times 10^{-2}}\)
= 1 x 10³l²mol^-2

(i) Kelvin-Planck statement: It is impossible to construct a machine that absorbs heat from a hot source and converts it completely into work by a cyclic process without transferring a part of heat to a cold sink.
(ii) Clausius statement: It is impossible to transfer heat from a cold reservoir to a hot reservoir without doing some work.
(iii) Entropy statement: The entropy of an isolated system increases during a spontaneous process

1) The unit of molecular mass is atomic mass unit [amu]. The unit of molar mass is gram per mole.
2) Molecular mass is the mass of one molecule while molar mass is the mass of one mole of molecules (6.022 x 10²³)
(i) Molecular mass of CO₂ = 1(C) + 2(0) = 12 + 32 = 44 amu
or 7.304 x 10^-23 g
(ii) Molar mass of CO₂ = 44 g mol^-1.

The carbon monoxide of the water gas can be converted to carbon dioxide by mixing the gas mixture with more steam at 400^oC and passed over a shift converter containing iron/copper catalyst. This reaction is called as water-gas shift reaction.
CO + H₂O ➝ CO₂ + H₂

(i) According to aufbau's principle 5th period has nine orbital (one 5s, five 4d and three 6p) to be filled.
(ii) Nine orbitals can accommodate a maximum of 18 electrons. Hence fifth period of the periodic table should has 18 elements from rubidium (2 = 37) to Xenon (Z = 54).

Gases are very less denser. They have negligible intermolecular forces of attraction between the molecules. They are in continuous kinetic motion. So they won't settle at the bottom due to gravitational forces. The material that is most dense will sink to the bottom; the less denser will go up.

Mg (OH)₂ ; Magnesium hydroxide.

It binds with haemoglobin and form carboxy haemoglobin which impairs normal oxygen transport by blood and hence the oxygen carrying capacity of blood is reduced. This oxygen deficiency results in headache, dizziness, tension, Loss of consciousness, blurring of eye sight and cardiac arrest.

The word Aufbau in German means 'building up'. In the ground state of the atoms, the orbitals are filled in the order of their increasing energies. That is the electrons first occupy the lowest energy orbital available to them.
Once the lower energy orbitals are completely filled, then the electrons enter the next higher energy orbitals. The order of filling of various orbitals as per the Aufbau principle which is in accordance with (n + l) rule.