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WorksheetsCSHS S2 Year 12 Chemistry Exam 2017 Multiple Choice
Total questions: 25
Worksheet time: 50mins
What type of reaction is represented by the conversion of butan-1-ol to butanoic acid?
Addition
Hydrolysis
Oxidation
Substitution
Consider the following system, which is at equilibrium.
Ag+(aq) + Br –(aq) → AgBr(s) + heat
Which one of the following changes would cause a decrease in the concentration of silver ions, as the system re-establishes equilibrium?
Cooling the system.
Placing the system under higher pressure.
Stirring the equilibrium mixture.
Adding solid silver bromide to the system.
An organic substance has an empirical formula of C3H6O2. Which of the following is NOT a possible identity of the substance?
Propanoic acid
Ethyl methanoate
Methyl methanoate
Methyl ethanoate
Which of the following statements about the primary structure of proteins is correct?
They exhibit mainly hydrogen bonding within their structure.
They have been isolated from the same species of living organisms.
They have a specific sequence of amino acids.
They perform a similar function
Which one of the following 1.0 mol L–1 solutions will have the lowest pH?
Sodium ethanoate
Potassium carbonate
Ammonium chloride
Sodium phosphate
In which one of the following reactions is the underlined species acting as a
Bronsted-Lowry acid?
KHCO3(s) + H+(aq) → K+(aq) + H2O(ℓ) + CO2(g)
H2CO3(aq) + NaOH(aq) ↔ NaHCO3(aq) + H2O(ℓ)
CO2(g) + H2O(ℓ) ↔ H2CO3(aq)
CO32–(aq) + Ca2+(aq) → CaCO3(s)
In standardising a sodium hydroxide solution by titrating 20.00 mL aliquots against a standard hydrochloric acid solution, a student experienced difficulty in obtaining consistent values for the volume of titrant added. Which of the following sequential steps could be responsible for this lack of precision?
The burette was cleaned and rinsed thoroughly with the standard acid solution before being filled
Several 250 mL conical flasks were washed, and rinsed thoroughly with the sodium hydroxide solution
A clean pipette was rinsed with the sodium hydroxide solution and a 20.0 mL aliquot was carefully pipetted into each conical flask.
Approximately 20 mL of distilled water was added from a measuring cylinder to each flask followed by 2 drops of methyl orange indicator.
Which of the following combinations can be used to form a buffer solution?
i. NH3(aq) / NH4Cl(aq)
ii. HCl(aq) / NaCl(aq)
iii. HCl(aq) / NH4Cl(aq)
iv. H2PO4–(aq) / HPO42–(aq)
v. H2SO4(aq) / HSO4–(aq)
i and iv only
i, iv and v only
i, ii and iv only
iv only
Water can undergo self-ionisation according to the following reaction.
2 H2O(ℓ) ↔ OH–(aq) + H3O+(aq)
For pure water at 25 oC, the hydrogen ion (H+) concentration is 1.0 x 10–7 mol L–1 and the pH is 7.0. When the temperature is lowered, the pH of the water is observed to rise. Which of the following statements gives the best explanation for this observation?
The forward reaction is exothermic.
The concentration of OH–(aq) reduces, thus decreasing its acidity.
The concentration of OH–(aq) reduces, thus decreasing its acidity.
The concentration of the H3O+(aq) decreases.
Consider the short section of the polymer in the image shown. Which one of the following is the correct name for the monomer used to synthesise this polymer?
2,2-dichlorobut-1-ene
1,1-dichlorobut-2-ene
1,1-dichloro-2-methylethene
1,1-dichloropropene
Increasing carbon dioxide levels in the atmosphere cause the concentration of carbonic acid, H2CO3, to increase in the ocean. For which of the following aqueous species found in ocean water, does this cause an increased concentration?
i. OH–(aq)
ii. HCO3–(aq)
iii. H3O+(aq)
iv. Ca2+(aq)
i only
i, ii and iii
ii and iii
all of them
In which of the following processes is bromine being reduced?
i. PBr3 + Br2 → PBr5
ii. Br2 + H2O → Br– + HBrO + H+
iii. 2 Br– → Br2 + 2 e–
iv. HBrO3 + H2O2 → HBrO4 + H2O
i, ii and iv only
ii, iii and iv only
i and ii only
i and iv only
Which of the following statements about the cell is correct?
The key becomes the anode when the cell is operating.
The key will gradually lose mass as the electrolysis process continues over an extended period of time.
The cathode is the copper rod.
The purpose of the anode is to replenish and maintain a steady supply of cations in the solution.
Which one of the following statements is false?
Oxidation occurs at the copper electrode.
The purpose of the battery is to provide a flow of electrons from anode to cathode.
Cations move through the solution from the cathode to the anode.
Reduction occurs at the site where electrons are made available.
Use the table of standard reduction potentials to determine which of the following reactions are likely to occur spontaneously under standard conditions.
i. H2(g) + Br2(aq) → 2 Br –(aq) + 2 H+(aq)
ii. Cu(s) + 2 H+(aq) → Cu2+(aq) + H2(aq)
iii. Sn(s) + Cd2+(aq) → Sn2+(aq) + Cd(s)
iv. H2O2(aq) + Zn2+(aq) → O2(g) + 2 H+(aq) + Zn(s)
i and iv only
i only
iii and iv only
iv only
Which one of the following reasons best explains why this cell is described as a fuel cell?
It is an efficient and reliable energy source that can be used to replace fossil fuels.
It can be recharged as both half-reactions are easily reversible.
It requires the reactants to be continuously supplied to the cell during operation.
It requires that one of the reactants to be a liquid and the other to be a gas for optimal operation.
Which one of the following is the overall equation for the cell?
O2(g) + 2 H2O(ℓ) → 4 OH–(aq) + 2 O2– (aq)
2 CH3OH(ℓ) + 4 H2O (ℓ) → 16 OH–(aq) + 2 CO2 (g)
4 H2O(ℓ) + 2 CO2(g) → 3 O2(g) + 2 CH3OH(ℓ)
3 O2(g) + 2 CH3OH(ℓ) → 4 H2O(ℓ) + 2 CO2(g)
The theoretical voltage obtainable from this cell under standard conditions is:
1.10V
1.50V
0.30V
0.70V
The two organic substances shown in the image were reacted together under favourable conditions and a new product was formed. Which one of the following could be produced from this reaction?
A protein
A fatty acid
A soap
A polyester
Which of the following pairs of compounds would form ethyl butanoate when warmed with concentrated sulfuric acid?
CH3CH2OH and CH3CH2COOH
CH3CH3CH3CH2OH and CH3COOH
CH3CH2CH2COOH and CH3CH2OH
CH3COOH and CH3CH2CH2OH
Consider the two α-amino acids, X and Y, shown in the image. The correct names for these two α-amino acids are:
alanine and valine respectively.
valine and threonine respectively.
serine and alanine respectively.
serine and lysine respectively.
The image shows an energy profile diagram for a chemical reaction. The reaction is:
Exothermic with an activation energy of +400 kJ mol L-1
(b) Endothermic with an activation energy of +250 kJ mol L-1
Exothermic with an of enthalpy change +150 kJ mol L-1
Endothermic with an enthalpy change of +150 kJ mol L-1
Which one of the following lists places the compounds in their correct class?
Which of the compounds shown above can be identified by using litmus paper alone?
i and iv
i and ii
ii and iii
i only
An enzyme is a biological catalyst. An esterase enzyme can be used in the hydrolysis of an ester as shown in the image.
Upon the addition of esterase, which of the following statement is correct for this process?
The position of equilibrium for this reaction is shifted to the right.
The rates of the forward and reverse reactions both increase equally.
The rate of the forward reaction increases more than the rate of the reverse reaction.
The rate of the forward reaction increases while the rate of the reverse reaction decreases.
