Regents Chemistry Test Preparation Practice

    Moles And Stoichiometry

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    Base your answers to questions 8 on the information below.

    Two hydrocarbons that are isomers of each other are represented by the structural formulas and molecular formulas below.

    chemical-bonding, chemical-bonds, organic-chemistry, hydrocarbons, organic-chemistry, hydrocarbons fig: chem12012-exam_g15.png

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    Base your answers to questions 9 on the information below.

    During a fireworks display, salts are heated to very high temperatures. Ions in the salts absorb energy and become excited. Spectacular colors are produced as energy is emitted from the ions in the form of light.

    The color of the emitted light is characteristic of the metal ion in each salt. For example, the lithium ion in lithium carbonate, Li2CO3, produces a deep-red color. The strontium ion in strontium carbonate, SrCO3, produces a bright-red color. Similarly, calcium chloride is used for orange light, sodium chloride for yellow light, and barium chloride for green light.

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    Base your answers to questions 10 on the information below.

    Vitamin C, also known as ascorbic acid, is water soluble and cannot be produced by the human body. Each day, a person’s diet should include a source of vitamin C, such as orange juice. Ascorbic acid has a molecular formula of C6H8O6 and a gram-formula mass of 176 grams per mole.

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    Base your answers to questions 11 on the information below.

    The equation below represents the reaction between 1-butene and bromine to form the compound 1,2-dibromobutane, C4H8Br2.

    organic-chemistry, hydrocarbons, chemical-bonding, chemical-bonds, organic-chemistry, hydrocarbons fig: chem12013-exam_g17.png

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    Base your answers to questions 12 on the information below.

    Nitrogen gas and oxygen gas make up about 99% of Earth’s atmosphere. Other atmospheric gases include argon, carbon dioxide, methane, ozone, hydrogen, etc.

    The amount of carbon dioxide in the atmosphere can vary. Data for the concentration of CO2(g) from 1960 to 2000 are shown in the table below.

    periodic-table, identification-of-element fig: chem12013-exam_g19.png

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    Base your answers to questions 13 on the information below.

    The element boron, a trace element in Earth’s crust, is found in foods produced from plants. Boron has only two naturally occurring stable isotopes, boron-10 and boron-11.

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    Base your answers to questions 14 on the information below.

    The active ingredient in the pain reliever aspirin is acetylsalicylic acid. This compound can be produced by reacting salicylic acid with acetic acid. The label of one aspirin bottle indicates that the accepted mass of acetylsalicylic acid in each tablet is 325 milligrams.

    In a laboratory, an aspirin tablet is crushed and mixed with water to dissolve all of the acetylsalicylic acid. The measured pH of the resulting solution is 3.0.

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    Base your answers to questions 15 on the information below and on your knowledge of chemistry.

    Ethene and hydrogen can react at a faster rate in the presence of the catalyst platinum. The equation below represents a reaction between ethene and hydrogen.

    moles-and-stoichiometry, formula-mass-and-gram-formula-mass, moles-and-stoichiometry, compounds fig: chem12014-exam_g9.png

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