Chemistry Question Answer 2022

Chemistry 1
CHEMISTRY
By Name
Course
Instructor
Institution
Location
Date

Chemistry 2
Question one
From the reversible reaction below
The initial values of moles of CO (nCO) = 0.36, the number of moles of H2 (nH2) =
0.64, the temperature is 1500C = 423 K . The container volume = 10 litres
At equilibrium the number of moles of CH3OH ( nCH3OH) = 0.12
Part a
Kc
The mole ratio between Co : H2 = 0.36: 0.64.
At equilibrium 0.36-x 0.64-x
Kc = Kn ( ¿
X= 0.12 ( given)
Kn = ( nCH 3 OH
(nCO )¿ ¿
VT ( the totalvolume ) = 10 litres
∆ ng = change in the number of moles = 1-(1+2) = -2
Kc= x
( 0.36−x ) ¿ ¿
Kc= 0.12
( 0.36−0.12 ) ¿ ¿
Kc= 3.125 (100) = 312.5
Part b
Kp = kc (RT¿∆ ng
Kp= ( 312.5) ( 0.0821)( 423 ¿−2 Temperature = 423 K ( given)
Kp = 312.5
¿ ¿

Chemistry 3
Part c
Since change in temperature is negative, the reaction is exothermic,
i.
If the pressure is increased by keeping temperature constant , the reaction will
move in a direction where partial pressure of the gas decreases and we know that
pressure is directly proportional to number of moles . Thus increasing the pressure ,
the reaction will move in a direction where the number of moles decreases .
Therefore here, the number of moles of product is less than the number of moles of
reactant thus the reaction will move into the forward direction.
ii.
This reaction is exothermic in nature. Therefore if we increase the temperature, the
reaction will move into backward direction to decrease the temperature.
Question two
Part a
i.
largest atom is Na : elecronic configuration of Na : [Ne] 3s1 ; Mg : [Ne] 3s2 ; Al: [Ne] 3s2 3p1 .
Since with increasing atomic No. there is increse in effectuve nuclear charge, with additional
electrons added to new shell.
ii.
Largest atom is Rb : elecronic configuration of Na : [Ne] 3s1 ; K : [Ar] 4s1 ; Rb : [Kr] 5s1 ; since new
shell is added down in group
Part b
Al : [Ne] 3s2 3p1 : = Lowest energy orbitals fill first : in n=3 shell lowest energy orbital '3s' filled
first. (The orbital in a subshell are degenerate (same energy), the whole subshell of a given type of
orbital is occupied before going on to adjacent subshell of higher energy). Just 2 electrons are
allowed for every orbital and they have to be of contrasting spin. The most steady electron
configuration in a subshell happens when the optimum number of non-paired electrons occur, all will
have direction of the same spin.
Part c
element symbol electron protons No. of Neutrons
Magnesium Mg 12 12 12