The general formula of alkanones is
A. RCHO
B. R2CO
C. RCOOH
D. RCOOR
Answer: B
Alkanones ( ketones) have the general formula R2CO.
Where R can be an alky gp
The constituent common to duralumin and alnico is
A. Co
B. Mn
C. Al
D. Mg
Answer: C
Constituents of Duralumin are: Al, Cu, Mg, Mn.
Constituents of Alnico are: Al, Ni and Co
The shape of the S-orbital is
A. elliptical
B. spiral
C. circular
D. spherical
Answer: D
Aluminium hydroxide is used in the dyeing industry as a
A. dye
B. dispersant
C. salt
D. mordant
Answer: D
The tincture of iodine means iodine dissolved in
A. ethanol
B. bromine chloride
C. chlorine water
D. water
Answer: A
Temporary hard water is formed when rain water containing dissolved carbon(IV) oxide flows over deposits of
A. CaCO3
B. Na2CO3
C. Na2SO4
D. CaSO4
Answer: A
CaCO3 + CO2 + H2O → Ca(HCO3)2
The acid anhydride that will produce weak acid in water is
A. SO3
B. NO2
C. SO2
D. CO2
Answer: D
CO2 combines with water to give a weak trioxocarbonate (IV) acid.
CO2 + H2O → H2CO3
H2CO3 is an example of a weak acid
The process that occurs when two equivalent forms of a compound are in equilibrium is
A. Isotopy
B. Resonance
C. Isomerism
D. Reforming
Answer: B
In the laboratory preparation of ethyl ethanoate, the water present in the mixture is removed using a solution of
A. an hydrous CaCl4
B. concentrated NaCO4
C. dilute NaOH
D. concentrated H4SO4
Answer: D
This is used in the preparation of ethyl ethanoate to remove the water present since it serves as a dehydrated agent.
The constituent of air necessary in the rusting process are
A. O2 and H2O
B. Ar and CO2
C. CO2 and H2O
D. O2 and CO2
Answer: D
Note water is importance but going by the options, D is the best
For a general equation of the nature xP + yQ → mR + nS, the expression for the equilibrium constant is
A. k [P]x [Q]y
B. 
C. 
D. 
Answer: C
A given mass of gas occupies 2dm3 at 300k. At what temperature will its volume be doubled, keeping the pressure constant?
A. 400k
B. 480k
C. 550k
D. 600k
Answer: D
At constant pressure connotes Charle’s law
V1T1 = V2T2
2dm3/300k = 2 x 2dm3/T2
T2= 600k
The oxidation number of iodine in KIO3 is
A. +7
B. +3
C. +5
D. +6
Answer: C
An isomer of C5H12 is
A. 2–ethyl butane
B. butane
C. 2–methyl butane
D. 2–methyl propane
Answer: C
C5H12 has 5 carbons acid 12 hydrogens.
2–methyl butane have carbon=5 and hydrogen=12
When few drops of concentrated trioxonitrate(V) acid is added to an unknown sample and wanned an intense yellow colouration is observed. The likely functional group present in the sample is
A. NH3—C—C=O
B. CHO
C. CO
D. CNH2
Answer: A
Xanthopreitic test for the presence of protein, when conc nitric acid is added to the drop, an intense yellow colouration is observed.
A sample of orange juice is found to have a PH of 3.80. What is the concentration of the hydroxide ion in the juice ?
A. 1.6 × 10-4
B. 6.3 × 10-11
C. 6.3 × 10-4
D. 1.6 × 10-11
Answer: B
PH = – Log[ H+ ]PH + POH =14
POH = 14 – 3.8
POH = 10.2
POH = – Log[ OH– ]
10.2 = – Log[ OH– ]
10-10.2 = [ OH– ]
[ OH– ] = 6.3 x 10-11
Incomplete oxidation of ethanol yields
A. CH3COOH
B. CH3COCH3
C. CH3CH2OCH2CH3
D. CH2CHO
Answer: D
Ethanol…..oxidation Ethanal……..Ethanoic Acid
Primary alcohol oxidises to aldehyde and later to carboxylic acid.
Secondary alcohol oxidises to ketones.
Ethanol is an example of primary alcohol and primary alcohol can be oxidised to aldehyde and carboxylic acid. Wherein, incomplete oxidation of primary alcohol yields aldehyde also known as alkaline while complete oxidation of primary alcohol yields carboxylic acid.
The salt formed from a weak acid and a strong base hydrolyzes in water to form
A. A saturated solution
B. an acidic solution
C. a buffer solution
D. an alkaline solution
Answer: D
This is a solution formed from the hydrolyses of an alkali in water.
The ideal gas laws and equations are true for all gases at
A. low pressures and lower temperatures
B. low temperatures and high pressures
C. high pressures and high temperatures
D. low pressure and high temperatures
Answern: D
At high temperature and low pressure, the vander waal equation is reduced to ideal gas equation.
i.e, [P + av2] [v – b] = RT is reduced to PV = nRT
Generally, a gas behaves more like an ideal gas at higher temperature and lower pressure
When ΔH is negative, a reaction is said to be
A. endothermic
B. exothermic
C. reversible
D. ionic
Answer: B
When ΔH is negative, heat is liberated to the surrounding and it connotes an exothermic reaction.ΔH = −ve
A. 226
B. 220
C. 227
D. 222
Answer : D
42He = alpha particle
considering the summation of the mass number
226 = x + 4
x = 226 + 4
x = 222
The shape of ammonia molecules is
A. trigonal planar
B. octahedral
C. square planar
D. tetrahedral
Answer: A
The mass of silver deposited when a current of 10A is passed through a solution of silver salt for 4830s is – (Ag = 108 F = 96500(mol-1)
A. 54.0g
B. 27.0g
C. 13.5g
D. 108.0g
Answer: A
Recall thatm = MmIt / 96500n
Mm =108, t = 4830s
I = 10A, n = 1
m = 108 × 10 × (483096500) × 1
m = 54.0g
Mass deposited = Mm × It/96500n
Answer: A
Calculate the amount in moles of silver deposited when 9650C of electricty is passed through a solution of silver salt [= 96500 Cmol-1]
A. 0.05
B. 10.80
C. 10.00
D. 0.10
Answer: D
Solutionwhere Q = IT
M = Mm × Q /96500n
where m = mass
Mm = Molar mass
Q = Quantity of electricity
n = number of change= +1
M / Mm = mole = mass / Molarmass
M /Mm = Q / 96500n
= 965096500n × 1
= 110 = 0.1mol
The reaction of halogens in the presence of sunlight is an example of
A. oxidation reaction
B. addition reaction
C. hydrogenation reaction
D. substitution reaction
Answer: D
The enzyme used in the hydrolysis of starch to dextrin and maltose is
A. amylase
B. diastatse
C. invertase
D. zymase
Answer: B
This is any amylase or a mixture of amylases that converts starch to dextrin and maltose
The alkyl group is represented by the general formula.
A. CnH2n
B. CnH2n − 2
C. CnH2n + 1
D. CnH2n + 2
Answer: C
CH2S(g) + O2(g) → 2Cn + SO2(g)
What is the change in the oxidation number of copper in the reaction?
A. 0 to + 2
B. 0 to + 1
C. C + 1 to 0
D.+ 2 to + 1
Answer: C
In the reactant;
Cu2S
2 Cu – 2(1) = 0
2 Cu = 2
Cu = 22
Cu = +1
In the product, Cu
Cu = O
The oxidation number of Cu in Cu2S and Cu respectively is +1 and 0 respectively
In the diagram above. X is
A. SO3
B. SO2
C. S
D. H2S
Answer: B
The setup represents the production of sulfur dioxide. And the cylinder marked X is SO2
The diagram above. Y is
A. fused CaO
B. H2O
C. NaOH
D. Concentrated H2SO4
Answer: D
Calculate the mass of copper deposited when a current of 0.5 ampere was passed through a solution of copper(II) chloride for 45 minutes in an electrolytic cell. [Cu = 64, F = 96500Cmol-1
A. 0.300g
B. 0.250g
C. 0.2242g
D. 0.448g
Answer: D
= MmIT /96500n
Copper II Chloride = CuCl2
CuCl2 → Cu2+ + 2Cl2
Mass of compound deposited = Molar mass × Quantity of Electricity / 96500 × no of charge
Q = IT
I = 0.5A
T = 45 × 60
T = 2700s
Q = 0.5 × 2700
= 1350c
Molarmass = 64gmol-1
no of charge = + 2
Mass = 64×135096500×2
Mass = 0.448g
C3H5 – COH3 =CH2
The IUPAC nomenclature of the structure above is
A. 3-methybut-3-ene
B. 2-methylbut-1-ene
C. 2-ethylprop-1-ene
D.2-methylbut-2-ene
Answer : B
Answer: C
4Fe + 3O2 → 2 Fe2O2
Fe2O3 + H2O → Fe2O3.H2O
Answerv: C
Graham’s Law of diffusion of gas. The rate of dimension of a gas inversely proportional to the square root of its molecular mass or its density, which is R ∝ 1 / √Mm or R ∝ 1 /√D Dx = 0.5gdm-3, Dy = 2gdm-3 R= K /√D R √D = k R1D1 = R1D2 RxDx = RyDy RxRy = DyDx = 20.5 = 2.0The carbon atoms on ethane are
A. sp2 hybridized
B. sp3 hybridized
C. sp4 hybridized
D. sp hybridized
Answer : B
Alkane’s family are sp3 hybridized. It is tetrahedral.
While:
Alkenes are sp2 hybridization
Alkyne are sp hybridized
According to Charle’s law, the volume of a gas becomes zero at
A. −100°c
B. −273°c
C. −373°c
Answer : B
Solution
Answer: B
Mm of XO2 = x + 16(2) = x + 32
vapour density = 32
∴ x + 32 = 32 × 2
x + 32 = 64
x = 64 – 32
x = 32
∴ the relative molecular mass of X is 32
Relative molecular mass = vapour density × 2
The gas that can be collected by downward displacement of air is
A. chlorine
B. sulphur (IV) oxide
C. carbon (IV) oxide
D. ammonia
Answer: D
Answer: D
Bubbling of air through the acid solution removes deposited oxides of nitrogen.
Answer: D
Ethene is prepared industrially by
A. Reforming
B. Polymerization
C. Distillation
D. Cracking
Answer: D
C15H32 → 2C2H4 + C3H6 + C8H14
……Δheat…ethene….
Correct Option: A
SolutionAmount in moles = n
Volume v = 10.5dm3
Pressure P = 6atm
Temperature T = 30°C + 273 = 303k
R, Gas constant = 0.082 atmdm3k-1 mol
Recall from ideal gas equation
pv = nRT
n = RV /RT
n = 6×105 /0.082×303
n= 2.536mol
Answer: C
Na is kept under kerosene (paraffin) to avoid reactivity with air.
.
The furring of kettles is caused by the presence in water of
A. calcium hydrogentrioxocarbonate (IV)
B. calcium trioxocarbonate (IV)
C. calcium tetraoxosulphate (VI)
D. calcium hydroxide
Answer: B
Furring of kettles is caused by the temporary hardness in water as a result ofCaCO3
Answer: B
Answer: B
the chemical equation.
Ca[OH]2 + 2NH4Cl → CaCl2 + 2H2O + 2NH3
X = NH3
Answer: D
ΔG= ΔH − TΔS.
To determine whether ΔG will be positive or negative, the value of ΔH(change in enthalpy) and ΔS (change in entropy) must be given. Likewise the temperature.
