Hsc Chemistry - Module 1
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The following reaction occurs during the cracking of hydrocarbon molecules: C18H36 --> 2C8H16 + Z What is the name of compound Z?
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Ethylene
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Ethane
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Propene
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Butane
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This HSC Chemistry Module 1 quiz assesses knowledge on organic chemistry, particularly focusing on reactions and properties of hydrocarbons and polymers. It evaluates understanding of chemical reactions, polymer production, and analytical techniques to distinguish chemical compounds, providing essential insights for advanced chemistry studies.
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- 2.
Bromine water is reacted with ethylene in a test tube. Which alternative most correctly predicts the product(s) of this reaction?
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1-Bromoethane
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1,2-dibromoethylene
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1-Bromoethylene + HBr
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2-Bromoethanol
Correct Answer
A. 2-BromoethanolExplanation
When bromine water reacts with ethylene, the bromine is added across the double bond of ethylene. This results in the formation of 2-Bromoethanol, where the bromine atom is attached to one of the carbon atoms in ethylene and the hydroxyl group (OH) is attached to the other carbon atom. This is the most likely product of the reaction based on the reaction conditions and the properties of bromine water.Rate this question:
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- 3.
Which of the following reagents would best be used to distinguish between propene and propane?
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Phenolphthalein
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Universal Indicator
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Bromine Water
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Hydrochloric Acid
Correct Answer
A. Bromine WaterExplanation
Bromine water would best be used to distinguish between propene and propane because it can react with the double bond in propene, causing the bromine water to decolorize and turn from orange to colorless. On the other hand, propane does not have a double bond and therefore will not react with bromine water. The decolorization of bromine water is a characteristic test for unsaturation, which propene possesses.Rate this question:
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- 4.
The following graph shows the molecular weights of the molecules present at one instant during the polymerisation of ethylene. This graph tells us that:
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Polymer molecules are made quickly at first and then more slowly.
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At any instant during polymerisation the polymer molecules present vary in size.
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The polymer molecules formed have a curved shape.
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The polymer molecules formed first are quite long, but they become shorter with time.
Correct Answer
A. At any instant during polymerisation the polymer molecules present vary in size.Explanation
The graph shows that the molecular weights of the molecules present at one instant during the polymerization of ethylene are not all the same. This indicates that the polymer molecules present vary in size at any given time during the polymerization process.Rate this question:
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- 5.
Identify the steps in the production of polyethylene in order of occurrence.
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Combustion, oxidation, reduction.
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Initiation, propagation, termination.
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Distillation, catalysis, polymerisation.
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Addition, hydration, fermentation.
Correct Answer
A. Initiation, propagation, termination.Explanation
The correct answer is "Initiation, propagation, termination." In the production of polyethylene, initiation is the first step where a catalyst is used to start the reaction. Propagation follows, where monomers continuously add to the growing polymer chain. Finally, termination occurs when the reaction stops, resulting in the formation of the polyethylene.Rate this question:
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- 6.
Of the following statements, which can be applied to the formation of a condensation polymer?
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The condensation of water is always involved.
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The condensation polymer and another small molecule form.
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Two or more monomers condense together.
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Biomass is always used.
Correct Answer
A. The condensation polymer and another small molecule form.Explanation
The formation of a condensation polymer involves the condensation reaction between two or more monomers, resulting in the formation of a polymer chain and the release of a small molecule, such as water. This process occurs without the requirement of biomass. Therefore, the statement "The condensation polymer and another small molecule form" is the only statement that can be applied to the formation of a condensation polymer.Rate this question:
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- 7.
Cellulose is a major component of biomass. Which of the following is largely composed of cellulose?
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Cell walls of plants.
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Cytoplasm of plant cells.
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Flowers.
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Nuclei of the cells of land plants.
Correct Answer
A. Cell walls of plants.Explanation
The cell walls of plants are largely composed of cellulose. Cellulose is a complex carbohydrate that provides structural support to plant cells. It forms a strong and rigid network of fibers, giving strength to the cell walls. This allows plants to maintain their shape and withstand external pressures. Cellulose is not found in the cytoplasm, flowers, or nuclei of plant cells.Rate this question:
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- 8.
Identify the product formed by the dehydration of ethanol.
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Ethylene
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Methanol
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Ethane
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Methane
Correct Answer
A. EthyleneExplanation
The correct answer is ethylene. Dehydration of ethanol involves the removal of a water molecule, resulting in the formation of ethylene. Ethylene is an organic compound commonly used in the production of plastics, solvents, and as a ripening agent for fruits. It is a colorless gas with a sweet odor and is highly flammable.Rate this question:
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- 9.
Identify a catalyst used for the dehydration of ethanol.
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Platinum
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Concentrated sulfuric acid
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Zeigler-Natta catalyst
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Iron (II) oxide
Correct Answer
A. Concentrated sulfuric acidExplanation
Concentrated sulfuric acid is commonly used as a catalyst for the dehydration of ethanol. This reaction involves removing a water molecule from ethanol to form ethene. Sulfuric acid acts as a strong acid, providing protons that can protonate the hydroxyl group of ethanol, making it a better leaving group. This enhances the elimination of water and promotes the formation of ethene. Additionally, sulfuric acid can also act as a dehydrating agent by absorbing water formed during the reaction, driving the equilibrium towards the production of more ethene.Rate this question:
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- 10.
The correct value for the heat of combustion of ethanol is 1367kJ/mol. A group of students performed an experiment to measure the heat of combustion of ethanol and obtained the following results after three trials: 254kJ/mol 252kJ/mol 256kJ/mol Identify an acceptable statement based on these results:
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The results were not reliable as they consistently gave very low values.
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The results are inaccurate so they are not reliable.
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The results are not valid because they are wrong.
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The results obtained for ethanol are reliable.
Correct Answer
A. The results obtained for ethanol are reliable.Explanation
Based on the consistent values obtained in the three trials, it can be concluded that the results for the heat of combustion of ethanol are reliable. The fact that the values are close to each other suggests that the experiment was conducted accurately and with precision. Therefore, we can trust the obtained results for ethanol.Rate this question:
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- 11.
Which of the following would you expect to provide the most valid information about the usefulness of ethanol as a fuel?
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A company which manufactures ethanol for use as a fuel.
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A company which produces petrol for automobiles.
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A scientific research organisation funded by the government or private companies.
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A scientific research organisation which is self-funded by sales of publications.
Correct Answer
A. A scientific research organisation which is self-funded by sales of publications.Explanation
A scientific research organization that is self-funded by sales of publications would provide the most valid information about the usefulness of ethanol as a fuel. This is because being self-funded by sales of publications indicates that the organization is independent and not influenced by any external interests. Therefore, their research and findings are likely to be unbiased and reliable, making their information about the usefulness of ethanol as a fuel more valid.Rate this question:
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- 12.
A piece of coper is placed into a solution of sodium chloride soluton. There is no visible reaction. What can you deduce about the relative reactivity of copper and sodium?
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Copper and sodium are both unreactive metals.
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Copper and sodium are identical in reactivity.
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Copper is more active than sodium.
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Copper is less active than sodium.
Correct Answer
A. Copper is less active than sodium.Explanation
Based on the given information, when copper is placed into a solution of sodium chloride and there is no visible reaction, it can be deduced that copper is less reactive than sodium. This means that copper is less likely to undergo a chemical reaction compared to sodium when in contact with the sodium chloride solution.Rate this question:
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- 13.
The oxidation of zinc is shown by the equation: Zn (s) --> Zn2+ + 2e- During this reaction, the oxidation state changes from 0 for zinc to +2 for the zinc ions. Which statement best describes and accounts for this change in oxidation state?
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It has decreased due to the loss of electrons from the zinc metal.
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It has increased due to the loss of electrons from the zinc metal.
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It has decreased due to the loss of electrons from the zinc ions.
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It has increased due to the loss of electrons from the zinc ions.
Correct Answer
A. It has increased due to the loss of electrons from the zinc metal.Explanation
The oxidation state of an element refers to the number of electrons that an atom gains or loses when it forms a compound or ion. In this case, the oxidation state of zinc changes from 0 (in the solid state) to +2 (in the form of zinc ions). This change indicates that zinc has lost two electrons during the reaction, resulting in an increase in its oxidation state. Therefore, the statement "It has increased due to the loss of electrons from the zinc metal" best describes and accounts for this change in oxidation state.Rate this question:
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- 14.
Which of the following equations shows the greatest change in oxidation state?
Correct Answer
A.Explanation
The equation that shows the greatest change in oxidation state is the one in which the element undergoes the largest change in the number of electrons gained or lost. This can be determined by comparing the oxidation states of the element in the reactant and product side of the equation. The equation with the highest difference in oxidation states indicates the greatest change in oxidation state.Rate this question:
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- 15.
In a galvanic cell, what do we call the electrode where oxidation occurs?
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Anolyte
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Catholyte
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Anode
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Cathode
Correct Answer
A. AnodeExplanation
In a galvanic cell, the electrode where oxidation occurs is called the anode. The anode is the site where electrons are released during the redox reaction, leading to the oxidation of the species present. It is important to note that oxidation always takes place at the anode in a galvanic cell, while reduction occurs at the cathode.Rate this question:
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- 16.
Cu-63 and Cu-65 are isotopes of copper, an element with atomic number of 29. What do the atoms of both Cu-63 and Cu-65 have in common?
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29 neutrons
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29 protons
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29 protons and 29 electrons
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29 neutrons and 29 electrons
Correct Answer
A. 29 protons and 29 electronsExplanation
Cu-63 and Cu-65 are isotopes of copper, meaning they have the same number of protons and electrons. Since copper has an atomic number of 29, both isotopes will have 29 protons and 29 electrons in their atoms.Rate this question:
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- 17.
The graph below shows the stages in the decay of an atom of uranium-238 used in reactors. Which of the following is a stable species?
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Pb-214
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U-238
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Pb-82
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Pb-206
Correct Answer
A. Pb-206Explanation
The decay of an atom of uranium-238 results in the formation of various isotopes, including lead isotopes. Pb-206 is a stable species because it is not radioactive and does not undergo further decay. This means that it does not continue to break down into other isotopes over time. In contrast, U-238 is radioactive and eventually decays into Pb-206, making it an unstable species. Pb-214 and Pb-82 are also unstable isotopes that are produced during the decay process of U-238.Rate this question:
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- 18.
Which of the following equations most correctly portrays a radioactive decay shown in the table below?
Correct Answer
A. -
- 19.
Small amounts of transuranic elements have been synthesised by scientists. Neptunium is a transuranic element which was synthesised and isolated in 1940. The reaction used to produce neptunium can be shown by the following incomplete equation: What is particle X?
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An electron
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A proton
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A neutron
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A positron
Correct Answer
A. A neutronExplanation
The reaction used to produce neptunium involves the synthesis and isolation of a transuranic element. Transuranic elements are elements with atomic numbers greater than that of uranium, and they are typically produced by bombarding a target material with high-energy particles. In this case, the reaction requires the addition of a neutron (particle X) to the target material in order to produce neptunium. Neutrons are electrically neutral particles found in the nucleus of an atom, and they play a crucial role in nuclear reactions and the stability of atomic nuclei.Rate this question:
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- 20.
Identify the list containing only elements with no stable isotopes.
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Mercury, sodium, aluminium.
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Polonium, radon, calcium.
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Radium, calcium, lead.
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Americium, curium, plutonium.
Correct Answer
A. Americium, curium, plutonium.Explanation
The elements mercury, sodium, aluminium, polonium, radon, calcium, radium, and lead all have stable isotopes. However, americium, curium, and plutonium do not have any stable isotopes. Therefore, the correct answer is Americium, curium, plutonium.Rate this question:
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.jpg "Which of the following equations most correctly portrays a radioactive decay shown in the table below?")
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Mar 22, 2023Quiz Edited by
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Jan 06, 2012Quiz Created by
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