NECO 2015 CHEMISTRY ANSWERS CHEMISTRY TYPE C. KNOW HOW YOU PERFORMED

1-10: BABDCDAADA
11-20: DDAEDDAEDC
21-30: CCEDADBBBB
31-40: ADCADDDEBB
41-50: CADCBABABC
51-60: BDECDDCCBA
PLS U MAY USE THE TYPE ABOVE EVEN IF IT
IS NOT THE TYPE U WERE GIVEN.
YOU CAN TRACE UR ANSWERS WITH THESE
TO UR PAPER TYPE
CHEMISTRY OBJ TYPE C:
1B-The collision between the gas
molecules
2A-1s^22s^22p^63s^23p^5
3B-negatively charged ion
4D-High pressures
5C-40
6D-I^-(aq)
7A-addition reaction
8A-can reach completion and by changing the
conditions can go back to
give the starting substances as products
9D-K^+
10A-calcium hydrogen trioxocarbonate (iv)is
decomposed by heat
11D-Monoclinic
12D-Tetraoxosulphate(vi)acid
13A-chromatography
14E-separating funnel
15D-Have the same number of valence
electrons
16D-The distance between the comparison
17A-acid
18E-SO4^2-
19D-2.24
20C-210.2
21C-oxidation
22C-benzophenol
23E-methyl propanoate
24D-zinc
25A-cooordiate covalent
26D-increase
27B-16.2
28B-beryllium and boron 29B-m proportional
as It
30B-electrons
31A-hydrogen and chlorine
32D-(-15)
33C-oxidation power
34A-H2S
35D-oxidation number
36D-iron
37D-6
38E-thermal oxidation
39B-150
40B-boyle's
41C-nature reactants
42A-H2O(l)->H2O(s)
43D-hydrogenation
44C-C4H10
45B-calcium
46A-brass
47B-carbon
48A-K2CO3
49B-32
50C-lactic
51B-monobasic
52D-Trioxonitrate(V)
53E-(238)(92)U
54C-helium
55D-54
56D-lithosphere
57C-efflorescence
58C-2,3-dimethylhexane 59B-glucose
60A-fructose
(1ai)
Physical
- physical change is reversible
- No new substance is formed Chemical
- chemical change is irreverssible
- New substance is formed.
(1aii)
(1). Downward delivery
(2). Upward Delivery
(3). Kipp Apparatus
(1bi)
- Hydrochloric Acid
- Ammonia gas
(1bii)
This due to their solubility
(1biii)
- A compound contains two or more
substances chemically combined together
- A mixture contains two or more substances
physically combined
together
(1ci)
Isotope is the atom having the same atomic
number but different mass
number.
(1cii)
Relative Atomic mass of chlorine
= (75/100)*(35) + (25/100) * (37)
= 26.25 + 9.25
= 35.5
(1ciii)
(1). Chlorine gas
(2). Sulphur(iv)oxide
(3). Nitrogen(Iv)oxide
(1civ)
(1). They have high melting and boiling point
(2). They conduct electricity in molten or
aqueous form
(2ai)
Ionization energy
(2aii)
Atomic radius
(2aiii)
Ionization energy increases across the
period because the number of electronic shell
increases
Atomic radius iincreases because the number
of increases
(2aiv)
-Diffusion
-Brownian motion
-Osmosis
(2bi)
Gaylussac's law of combining volume
states that the volumes of gases which take
part in a chemical reaction bear a
simple ratio to one another and to the volume
of the gases.
(2bii)
Given; nN2=0.64
nCO2=0.5
nO2=0.375
PT=PN2+PCO2+PO2
Molar mass of N2=14*2=28 Molar mass of
CO2=12+16*2=44
Molar mass of O2=16*2=32
PN2=(nN2/(nN2+nCO2+nO2))PT
PN2=(0.64/(0.64+0.5+0.375))*760
PN2=(0.64/1.515)*760
PN2=321'mmHg PCO2=(0.5/1.515)*760
=251mmHg
PO2=(0.375/1.515)*760
=188mmHg
(2ci)
The basicity of an acid is the number of
replaceable hydrogen ion in one
molecule of an acid
(2cii)
Tetyraoxosulphate(vi)acis is corrosive because
its concentrated form causes
serious burnt
(2ciii)
Acid salts-KHCO3
Basic salt-Na2CO3
(2di)
Deliquescence substance is a substance when
exposed to the atmosphere
absorb water from the atmosphere and
suddenly turn to solution
(2dii)
Calcium
(3a)
Diamond:
-Diamond is tetrahedral in nature
-Diamond is the hardest substance Graphite:
-Graphite is a crystalline solid
-Graphite has a low melting point
(3b)
-Limestone is used to produce the carbon
(iv)oxide
-Ammonia is used as catalyst
(3ci)
Heavy chemicals->Dye
Fine chemicals->H2SO4
(3cii)
I-The higher the surface area of reactants,the
higher the rate of reaction.Reactants in
powered form reacts faster than solid form
II-Catalyst helps to speed up the rate of
chemical reaction
III-Temperature;The higher the temperature of
reacting vessels,the
higher the rate of reaction
(3d)
-Because they have i8ncompletely filled
-orbital
-Because they exhibit co-ordinate bond
between molecules
-Because they have magnetic domain
(3e)
-Natural gas;It is used for cooking
-Bitumen;It is used for candle wax
(5ai)
-Evaporation
-Combustion
-Carbon cycle
(5aii)
I-Cathode is the negative electrode through
which current enters.Anode is
the positive electrode through which
current leaves
II-Conductors are solids which allow the
passage of electricity .Electrolyrtes are
solutions which conduct electricity
III-Strong acid is the acid which ionizes
completely in water.Concentrated acid
is the acid which contains no water dilution
(5bi)
Mass of copper(m)=MQ/nF 0.16
=(63.5*Q)/(2*96500)
Q=(0.16*2*96500)/63.5
Q=486.30
Q=I*t
48i6.30=I*(15*60)
I=486.30/900
I=0.54A
(5bii)
Burning:oxygen is not required for burning
while Rusting:oxygen is
required for rusting
(5biii)
-By electrolysis
-By putrification of ores
(5ci)
Sulphur
(5cii)
-Bauxite
-Cryolite
(5ciii)
-It speeds up the rate of chemical reaction
-It is not used up in reaction

SYMBOL CLASS FOR MATHS,PHYSICS, CHEMISTRY, ACCOUNT,

(1) / means division or divide
Examples:
2/2 means 2/2
2 whole no 3/4 means 2¾
M=wp+(1/3)yp^2 means m=wp + ¾y²
(2) Log means logarithm
Example: (8) Log5 (base 8) means Log₈5
(3) * means multiplication
Example: 2*2 means 2x2
(4) ^ means Raise to power
Examples:
3^(-1) means 3^-1
5^(2) means 5²
30cm^(-2) means 30cm^-2
(5) Tita means θ
Example: Tan tita means tan θ
(6) Pie means π
Example: Pie R sqr h means πr²h
(7) Base means subscript
Example: 2 Base 3 means A₃
(8) Sqr root means √
Examples:
√3-√6+2√3 means Root 3-root6+2root 3
√(¾) means sqr root(3/4)
(9) bar means a dash on top a number of letter
Example: X bar means x̅
(10) ---(1) means equation 1
(11) Proportional means ∝
Example: R is proportional to 3/4rut m means R ∝ ¾
(12) Alpha means α
(13) Beta means β
(14) Gamma means γ
(15) cube root means ∛
(16) Mu means μ
(17) Rho means ρ
(18) Delta means δ
(19) Sigma means σ
(20) Tau means τ
(21) Ohm means Ω
(22) Lamda means λ
(23) Omega means ω
(24) Intersection means ∩
Example: B intersection C means B∩C
(25) Union means U
Example: B union C means BUC
(26) Factorial means !
(27) complements in sets means ‘
(28) (aq),(g),(l),(s) is used in chemistry to show the state of matter in equations
(29) Equivalent to means ≡
(30) Not equal to means ≠
(31) Quotation means “ ”
(32) Less or equal to means ≤
(33) Greater or equal to ≥
Example: (3/4)>=(1/2) means ¾ ≥ ½
(34) Plus or minus (or +-) means ±
Example: (3/4)<=(1/2) means ¾ ≤ ½
(35) Element of means ∈
Example: 2 belongs to X or 2 is a member of X means 2∈X
(36) Percent or percentage means %
(37) Degrees Fahrenheit means ℉
(38) Degrees Celsius means ℃
(39) Universal set means ξ or U
(40) Null or empty set means ∅ or {}
(41) <RST means RŜT
(42) 2.S.F means 2 significant figures
(43) P=(2,3) means P={2,3} in sets
(44) Propotional to means ∝
(45) Therefore means ∴
(46) KNO(3)(s) means KNO₃(s)
(47) NaCl=> Na^(+) + Cl^(-) means NaCl → Na⁺+ Cl^-
(48) Summation means Ʃ
(49) Parallel lines means ǁ
(50) Perpendicular lines means ˩
(51) Reversible equation means ↔
(52) Infinity means ∞
(53) Approximately means ~
(57) Approximately equal to ≅

Other Symbols
(1) File means ɸ
(2) Δ means Change or Triangle
(3) slope or differentiation means dy/dx or ∂y/∂x or δy/δx or Δy/Δx
(4) Parenthesis means …
(5) Naira means ₦
(6) Integral means ∫
(7) Almost equal to means ≈
(8) For all means ∀
(9) There exist means ∃
(10) Epsilon means ε
(11) Vertical dots means ⁞

Tables, Radiativity Diagrams

Table1 A table of this would be computer as follows X:1,2,3,4 FX:4,6,8,10 F(X-Xbar):10,8,6,4 Table2 A table like this would be computed as follows Particulars: maintenance,salaries &wages, Purchase of Drugs, total Amount: 2500,1000,2000,5500

Logarithm Table Tabulate No:92.63,  Log:1.9667 No: 2.914,  Log: 0.4645 2.4312 Antilog = 269.9 Therefore 92.63*2.914=2.4312

Radiativity Diagram means (238)U(92)=>(234)Th(90) + (4)He(2)

This is computed  as follows (1)(-b± sqr rut(b^2-4ac))/2a (2)Sqr root ((2Qh)/100) (3)Xbar=Efx/ef (4)Summation (n=1 to infinity )P(n) (5)S.D= Sqr Rut ((Ef|x-xbar|^2))/Ef (6)R is proportional to1/ sqr rut

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