(1ai)
Ionic bond is the bond that exists between
metallic and non-metallic atoms.
(1aii)
I ionic bond,
II ionic and covalent bond +1y2+2x-2*3=0
(1bi)
Na2S2O3, 2+2x-6=0
2x=6-2
X=4/2=2
:. the oxidation number of sulphur in Na2S2O3 is 2
(1c) Faraday’s first law states that the
quantity of substance deposited
or liberated during electrolysis is
directly proportional to the amount
of current passing through the
electrolyte at constant temperature
an pressure at a given time i.e Q=it
(1d) i. SO3
ii.NaO
(1e)
i. Exothermic
ii. Endothermic
(1f)
i. It turns blue litmus paper red
ii. It turns red litmus to red
(1g)Efflorescence are substances
when exposed to the atmosphere,
they lose their water of crystallization to the atmosphere.
(1h) (i.) It is used in making typewriter ribbon
(ii.) for making shoe polish
(iii.) For making carbon black
(1i)
i. It is used for hardening of oil
ii. It is used in breaking heavy
hydrocarbon light fraction
iii. It is used in producing
esters for making soap
(1j) Recall,
m= MQ/nF,
where m= mass of sliver deposited.
Ag^+ + e^- –> Ag
n=1,
m/M=No of moles = 10920/1*96500
m/M=No of moles = 0.113 moles.
====================
PLS NOTE THAT ^ MEANS RAISE TO POWER.
====================
(2ai) This can be defined as
a substance formed when
an element gains or looses election
(2aii)
Isotopes: these are element
that exist with the same at
its first election,
in the valence shell while
aluminum while aluminum
retains two hence magnesium
will become more stable than aluminum.
(II) This is because the first i
onization energy increases
across the period
but decreases down the group
(2bii)
Na2O,MgO, Al2O3
(2c)
(1) Allotrope are atoms that exist in different
forms but have the same physical state
(ii)Diamond and Graphite
(iii)
-Diamond is used for making jeweleries
- Graphite is used for making lead pencil
(2d)
2Nacl+H2SO4 –> Na2SO4+2Hcl
(i)
-The gas turns blue litmus paper to red
-The gas is colourless
(ii)2Nacl+H2SO4–> Na2SO4+2Hcl
(2e)
Molar mass(gmol^-1)=mass/Amount.
Amount in moles= 5.68*10^-3/28.
Amount in moles=2.03*10^-4moles.
Amount in moles=0.000203moles.
(3aiii)
-it wastes soaps
- it causes furring of kettles and boilers
(3aiv)
-crude oil spillage
refuse and sewage
(3bi) water is a polar solvent which is an
excellent solvent for electrovalent substances
like NaCl but oil is non-polar which has little
affinity for hydroxyl ion
(3bii)
-as dehydrating agent
-as an acid
-as oxidizing agent
(3ci) oxygen and hydrogen chloride
(3cii.)
I-NaOH
II- because it is soluble in water.
(4ai)
I. Anode is the positive
electrode through which
current enters the electrolyte
II. Cathode is te negative electrode through which current leaves the electrolyte
(4aii)
I. Nacl–> Na+ Cl-
II. Alcl3–> Al^3+ cl-
Al2O3–>Al^3+ O2-
(4aiii) This is because the reaction of
sodium with water is very
explosive and violent but that of aluminum is not
(4bi) This is because one substance is
undergoing oxidation and another reduction at the same time.
(4bii) Cr2O7^-5 –> Cr^+2
Cl- –> Cl2.
(4c)
Current(I)=6A
Time(t)=1hr30mins
= (1*3600)+(30*60)
=3600+1800
=5400s
Quantity of Electricity(Q)
=I*t
=6*5400
=32400coulombus
m=MQ/nF
Al^3+ + 3e^- –> AL
n=3
m= 27*32400/3*96500
m=3.02g
Mass of aluminum deposited is 3.02g
