WorksheetsChemistry SK026 Paper 1
Total questions: 40
Worksheet time: 10hrs 36mins
Half-life for a radioactive element is 50 minutes. What is the time required for 87.5 % by mass for that element to decompose?
1.5 hours
2.00 hours
1.67 hours
2.50 hours
A 0.1326 g sample of magnesium was burned in an oxygen bomb calorimeter. The total heat capacity of the calorimeter and water was 5760 JoC-1. If the temperature rise of the calorimeter with water was 0.57 oC, calculate the enthalpy of combustion of magnesium.
-3280 kJ mol-1
-24.8 kJ mol-1
435 kJ mol-1
-602 kJ mol-1
Calculate the enthalpy change for the reaction:
C (graphite) + 2H2 (g) + 1/2 O2 (g) → CH3OH
Using the following information:
C (graphite) + O2 (g) → CO2 (g) ; ΔH= -393.5 kJ
H2 (g) + 1/2 O2 (g) → H2O (l) ; ΔH= -285.8 kJ
CH3OH (g) + 3/2 O2 (g) → CO2 (g) + 2H2O (l) ; ΔH= -726.4 kJ
-1691 kJ
-238.7 kJ
1691.5 kJ
47.1 kJ
Given the following notation for an electrochemical cell:
Pt (s) ∣ H2 (g) ∣ H+ (aq) ∣∣ Ag+ (aq) ∣ Ag (s)
What is the balanced overall cell reaction?
2 H+ (aq) + 2 Ag+ (aq) → H2 (g) + 2 Ag (s)
H2 (g) + 2 Ag (s) → 2 H+ (aq) + 2 Ag+ (aq)
H2 (g) + 2 Ag+ (aq) → 2 H+ (aq) + 2 Ag (s)
2 H+ (aq) + 2 Ag (s) → H2 (g) + 2 Ag+ (aq)
Which of the following statements about electrolysis is CORRECT?
Oxidation occurs at the cathode.
Electrons flow from the cathode to the anode in the external circuit.
The more reactive the metal, the less readily the metal is discharged during electrolysis.
The number of moles of a metal is deposited during electrolysis is proportional to the quantity of electricity used and the charge on metal ion.
Choose the optically active compound.
CH3CH2CH2OH
CH3CH2CH(OH)CH3
(CH3)3CCH2OH
CH3CH2CH(OH)CH2CH3
Compound F is polymerised to form PVA. Which statement is CORRECT about compound F?
Compound F is a cis isomer
Compound F is a trans isomer
Compound F has one chiral centre
Compound F has functional group isomers.
Which of the following compounds has geometrical isomers?
CH2=CHCH3
(CH3)2C=CHCH3
CH2=CH(CH3)
CH3CH=C(CH3)CH2CH3
Hess' Law states that the
enthalpy change at 25°C and 1 atm is the same for all reactions.
standard enthalpy change of a reaction is the same whether the reaction takes place in one step or in a series of steps.
standard enthalpy change of a reaction is the heat change of a reaction at 25°C and 1 atm.
Which of the following statements about chlorination of alkane is correct?
The chain initiation step involves the attack of chlorine radicals on alkane.
Sunlight supplies energy for the homolytic cleavage of C-H bonds in alkane
Chlorine radicals are produced by light catalysed fission.
Chlorine radicals are generated again in termination step.
Compound X with molecular formula C7H12 absorbs 1 mol of hydrogen on catalytic hydrogenation to yield a compound of molecular formula C7H14. Ozonolysis of X and subsequent treatment with zinc and water yields only Y.
The structure of compound X is
Which of the following can be used to differentiate benzene from toluene?
Brady's test
Tollens' reagent
Bromination in the presence of sunlight
Baeyer's Test
Refer the following reaction:
The reaction above can be carried out using?
H2O/H+, heat
KMnO4, OH-, cold
O3 followed by hydrolysis with Zn, H3O+
KMnO4, H+, heat
The mechanism of a reaction is shown above:
Which of the following statements is TRUE concerning this reaction?
This reaction is an electrophilic substitution
This reaction occurs with a single continuous step
This reaction occurs through two distinctive steps
The rate of reaction for this reaction only depends on the concentration of the hydroxide ion.
Which arrangement is correct for the reaction between compounds I,II and III with sodium hydroxide towards SN2 reaction?
I > II > III
I > III > II
II > I > III
II > III > I
Which of the following alcohols forms a ketone when oxidised?
1-propanol
methanol
2-methyl-2-propanol
2-propanol
All of this statement is true about phenol EXCEPT
produce a white precipitate with bromine water
produce ester when react with ethanoic acid
produce a purple complex with iron (II) chloride
a stronger acid than ethanol but weaker than ethanoic acid
What is the final product, B of the synthetic route above?
The most acidic compound of the following is
C6H5OH
CH3CH2OH
CH3COOH
CH3COCH3
What is the product of this reaction? :
CH3CH2CH2CONH2 + Br2 + NaOH → Product Z
CH3CH2CH2Br
CH3CH2CH2NH2
CH3CH2CH2COOH
CH3CH2CH2CH2OH
Which of the following compounds is expected to possess the lowest boiling point?
(CH3)3N
CH3CH2NHCH3
CH3CH2CH2OH
CH3CH2CH2NH2
The pI (isoelectric point) of lysine is 9.8. The structure for lysine at pH 13 is
Copolymer is a polymer that form from
one type of monomer
condensation reaction
additional reaction
two different monomer
The rate law for the dimerization of NO2 is Rate = k [NO2]2. Which of the following changes will change the value of the rate constant, k?
Raising the temperature
Doubling the total pressure of the system
Doubling the volume of the reaction vessel.
Lowering the temperature
The following diagram shows the enthalpy of solution of an ionic compound, MX.
ΔH1 is the ionisation energy
ΔH2 is the enthalpy of hydration
ΔH3 is the enthalpy of hydration
ΔH1 is the electron affinity energy
The electromotive force (e.m.f) of an electrochemical cell,
Zn (s) l Zn2+ (aq) ll Cu2+ (aq) l Cu (s)
can be increased by:
increasing the concentration of copper ions
increasing the concentration of zinc ions
enlarging the surface of the electrodes.
adding more batteries
Which of the following is TRUE about the C-H bond in alkane?
It is polar
It undergoes substitution with chlorine
It reacts faster with bromine than chlorine
It is ionic bonded.
Which statement is TRUE about this reaction?
NO2 attacks the benzene ring
The nitronium ion, NO2+ acts as electrophile
It is a nucleophilic substitution reaction
Benzene ring acts as electrophile.
Choose compound that can form 20 alcohol when treated with alkylmagnesiumhalide (Grignard reagent) and followed by hydrolysis?
CH3COCH2CH3
CH3CH(CH3)CH2CHO
CH3CH2C(=O)CH2CH3
Which of the following compounds CAN NOT be oxidised to carboxylic acid by treating with hot acidified potassium permanganate (VII) solution?
CH3CH2CH2OH
CH3CH(CH3)CHO
(CH3)3COH
CH3CH2OH
The odour of pineapple is due to the presence of ester with the molecular formula of C3H7COOC2H5. Which of the following pair of reactants would produce this ester?
C2H5OH + C3H7COOH
C2H5COCl + C3H7OH
C3H7OH + C2H5COOH
C3H7CH2OH + CH3COOH
Tertiary amine does not react with acyl chloride because
it is more polar
amine has higher boiling point than alkane and alkene
amine is soluble in water and can form hydrogen bond
it does not have hydrogen atom directly bonded to nitrogen atom.
When benzenesulphonyl chloride is added to compound X, a precipitate is formed which dissolves in excess KOH. The precipitate reappears when a mineral acid is added. X is ...
(CH3CH2)3N
CH3CH2NH2
CH3CH2CONH2
CH3CH2NHCH3
A protein is
a polysaccharide
a polymer of amino acids
a saturated ester of glycerol
one of the units composing a nucleic acid
Which of the following statement is true about aminoethanoic acid?
It exhibits optical isomerism
It exists in anionic form in acidic solution
It forms zwitterions in aqueous solution
It is soluble in non polar solvents.
Copolymer is best described as
an addition polymer
a naturally occurring polymer
polymer that softens upon heating and can be remould
a polymer consisting of more than one type of monomer
Which of the following is NOT a naturally occurring polymer?
Starch
Protein
Kevlar
Cellulose
The standard reduction potential for the half-cell reaction Fe3+ + e- → Fe2+ is +0.77V. Which cell would be used to determine this standard value?
Fe electrode in 1.0 M Fe 3+ solution against electrode in 1.0 M Fe2+
Pt electrode in 1.0 M Fe3+ against Pt in 1.0 M Fe2+
Fe electrode in 1.0 M Fe3+ and 1.0 M Fe2+ against a standard hydrogen electrode.
Pt electrode in 1.0 M Fe3+ and 1.0 M Fe2+ against a standard hydrogen electrode.
If a reaction is described as zero order with respect to reactant A, this means that
A is catalyst in the reaction
A is not involved in the rate determining step
The value of the rate constant is independent of A
The rate of reaction is inversely proportional to the concentration of A
Consider the reaction between iodoethane and aqueous sodium hydroxide. Which of the following best explains the function of OH- ion as a nucleophile in this reaction?
It is alkaline
It is negatively charged.
It has a lone pair of electrons
It has a highly electronegative oxygen atom
