RELEASED. NC Final Exam. Chemistry. Released Items. Student Name:

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1 Released Items Student Name: hemistry Public Schools of North arolina State oard of Education epartment of Public Instruction Raleigh, North arolina RELESE N Final Exam opyright 2016 by the North arolina epartment of Public Instruction. ll rights reserved.

2 HEMISTRY RELESE I TEMS 1 What is the chemical formula for magnesium bromate? Mgr Mgr 2 MgrO 3 Mg(rO 3 ) 2 2 How are compounds with metallic bonds similar to ionic compounds? oth tend to have double and triple bonds. oth tend to have low boiling points. oth tend to have poor conductivity. oth tend to have high melting points. 3 Which of these elements has the greatest atomic radius? H N l s RELESE 1 Go to the next page.

3 HEMISTRY RELESE I TEMS 4 How does the amount of heat energy change as a 250-g sample of water is heated from 5.0 to 30.0? The amount of heat energy increases, causing the water to sublime. The amount of heat energy increases, causing the water to evaporate. s the temperature increases, the amount of heat energy decreases. s the temperature increases, the amount of heat energy increases. 5 This graph represents data collected when a sample of a gas is uniformly cooled from 155. Temperature ( ) ooling urve of a Gas X Y Time (minutes) RELESE Why does the temperature of the sample remain constant between point X and point Y? because the sample is transitioning from a gaseous state to a solid state because the sample is transitioning from a gaseous state to a liquid state because the sample is transitioning from a solid state to a gaseous state because the sample is transitioning from a liquid state to a solid state 2 Go to the next page.

4 HEMISTRY RELESE I TEMS 6 The phases of a substance under various pressure and temperature combinations are shown on this phase diagram. Phase iagram of a Substance What occurs if the pressure of the substance at point F remains constant, and the temperature increases to point G? Pressure (atm) F Temperature (K) It will transition from a solid state to a liquid state. It will transition from a liquid state to a solid state. It will transition from a solid state to a gaseous state. It will transition from a gaseous state to a solid state. G RELESE 3 Go to the next page.

5 HEMISTRY RELESE I TEMS 7 The potential energy diagram of a chemical reaction is shown below. Which best describes the energy in the chemical reaction? Potential Energy (J) 10 Heat energy was released. Energy was lowered by a catalyst Potential Energy of a hemical Reaction Reaction oordinate 8 J of energy were required to start the reaction. 10 J of energy were required to start the reaction. RELESE 4 Go to the next page.

6 HEMISTRY RELESE I TEMS 8 This balanced chemical equation represents a chemical reaction: 6NO + 4NH 3 5N 2 + 6H 2 O What volume of NH 3 gas, at Standard Temperature and Pressure (STP), is required to react with 15.0 g of NO? 5.68 L 7.47 L RELESE 10.0 L 11.2 L 9 The equation represents a chemical reaction at equilibrium. Hl (aq) + Mg (s) Mgl 2 (aq) + H 2 (g) + heat What happens to the system when the temperature is decreased? The reaction shifts toward the right, and the amount of hydrogen gas increases. The reaction shifts toward the right, and the amount of hydrogen gas decreases. The reaction shifts toward the left, and the amount of hydrogen gas increases. The reaction shifts toward the left, and the amount of hydrogen gas decreases. 5 Go to the next page.

7 HEMISTRY RELESE I TEMS 10 This equation represents a chemical reaction at equilibrium: 2SO 2 (g) + O 2 (g) 2SO 3 (g) What will happen when the concentration of SO 3 is increased? The reaction shifts to the right, and concentrations of SO 2 (g) and O 2 (g) decrease. The reaction shifts to the right, and concentrations of SO 2 (g) and O 2 (g) increase. The reaction shifts to the left, and concentrations of SO 2 (g) and O 2 (g) decrease. The reaction shifts to the left, and concentrations of SO 2 (g) and O 2 (g) increase. RELESE 6 Go to the next page.

8 HEMISTRY RELESE I TEMS 11 student conducts an experiment to identify the ph of some common household substances. The data is recorded in this table. ph Values for ommon Household Substances Substance ph mmonia 11.9 rain leaner 13.5 Hand Soap 10.1 Lemon Juice 2.3 Vinegar 3.0 Water 6.8 Which substance would be classified as containing the highest concentration of hydroxide ions? mmonia rain leaner Lemon Juice Vinegar RELESE 12 newly synthesized ionic compound is placed in water to make an aqueous solution. Which best describes the new ionic solution? The ionic solution conducts electricity. The ionic solution dissolves nonpolar solutions. The ionic solution cannot conduct electricity. The ionic solution is a neutral solution. 7 Go to the next page.

9 HEMISTRY RELESE I TEMS 13 Why is potassium chloride able to dissolve in water? because potassium ions are attracted to the partial negative charge of hydrogen because potassium ions are attracted to the partial positive charge of hydrogen because potassium ions are attracted to the partial negative charge of oxygen because potassium ions are attracted to the partial positive charge of oxygen 14 Which occurs if an electron transitions from n = 5 to n = 2 in a hydrogen atom? Energy is absorbed, and visible light is emitted. Energy is released, and visible light is emitted. Energy is released, and visible light is not emitted. Energy is absorbed, and visible light is not emitted. 15 When a gamma ray is emitted by an element, what happens to the atomic mass and the atomic number? RELESE The atomic mass stays the same, and the atomic number stays the same. The atomic mass changes, and the atomic number stays the same. The atomic mass stays the same, and the atomic number changes. The atomic mass changes, and the atomic number changes. 8 Go to the next page.

10 HEMISTRY RELESE I TEMS 16 How does a single covalent bond between two carbon atoms compare to a double covalent bond between two carbon atoms? single covalent bond is stronger and has a longer bond length than a double covalent bond. single covalent bond is stronger and has a shorter bond length than a double covalent bond. single covalent bond is weaker and has a shorter bond length than a double covalent bond. single covalent bond is weaker and has a longer bond length than a double covalent bond. 17 How do the three isotopes Sn-116, Sn-118, and Sn-119 differ? Sn-116 has 166 neutrons, Sn-118 has 168 neutrons, and Sn-119 has 169 neutrons. Sn-116 has 116 neutrons, Sn-118 has 118 neutrons, and Sn-119 has 119 neutrons. Sn-116 has 66 neutrons, Sn-118 has 68 neutrons, and Sn-119 has 69 neutrons. Sn-116 has 50 neutrons, Sn-118 has 52 neutrons, and Sn-119 has 53 neutrons. 18 Which molecule contains a triple bond? F 2 O 2 l 2 N 2 RELESE 9 Go to the next page.

11 HEMISTRY RELESE I TEMS 19 Which of these compounds will form a precipitate when mixed with an aqueous solution of sodium sulfate, Na 2 SO 4? LiNO 3 KNO 3 Mg(NO 3 ) 2 a(no 3 ) 2 20 Solid chromium(ii) reacts with oxygen gas to form solid ro. What is this type of reaction? decomposition synthesis single replacement double replacement 21 Which element has 8 valence electrons? potassium oxygen helium neon RELESE 10 Go to the next page.

12 HEMISTRY RELESE I TEMS 22 How are the bonds formed in a polar covalent compound? Electrons are shared unequally. Electrons are shared equally. Electrons are gained. Electrons are lost. 23 In a chemical reaction, how does increasing the temperature of the reactants affect the reaction process? The reactants absorb more heat, which turns them into products faster. The activation energy is decreased, which makes the reaction proceed faster. The kinetic energy of the reactants increases, causing more effective collisions. The particles break down faster, increasing the surface area and the reaction rate. RELESE 11

13 HEMISTRY RELESE I TEMS hemistry RELESE Items nswer Key Question Number Question Type 2 orrect nswer Percent orrect 3 Objective 1 M 59% hm M 65% hm M 73% hm M 65% hm M 82% hm M 56% hm M 20% hm M 48% hm M 34% hm M 45% hm RELESE 11 M 53% hm M 48% hm M 56% hm M 67% hm M 32% hm M 52% hm

14 HEMISTRY RELESE I TEMS Question Number Question Type 2 orrect nswer Percent orrect 3 Objective 17 M 62% hm M 45% hm M 28% hm M 83% hm M 61% hm M 34% hm M 50% hm These released items were administered to students during a previous test administration. This sample set of released items may not reflect the breadth of the standards assessed and/or the range of item difficulty found on the N Final Exam. dditional information about the N Final Exam is available in the ssessment Specification for each exam located at 2 This N Final Exam contains only multiple-choice (M) items. 3 Percent correct is the percentage of students who answered the item correctly during a previous administration. RELESE 2

15 HEMISTRY RELESE I TEMS larifying Objectives escriptions Only clarifying objective descriptions addressed by the released items in this document are listed below. complete list of North arolina Essential Standards for Science may be reviewed at hm nalyze the structure of atoms, isotopes, and ions. hm nalyze an atom in terms of the location of electrons. hm Explain the emission of electromagnetic radiation in spectral form in terms of the ohr model. hm Explain the process of radioactive decay by the use of nuclear equations and half-life. hm ompare (qualitatively) the relative strengths of ionic, covalent, and metallic bonds. hm Infer the type of bond and chemical formula formed between atoms. hm Interpret the name and formula of compounds using IUP convention. hm ompare the properties of ionic, covalent, metallic, and network compounds. hm Infer the physical properties (atomic radius, metallic and nonmetallic characteristics) of an element based on its position on the Periodic Table. hm Explain heating and cooling curves (heat of fusion, heat of vaporization, heat, melting point, and boiling point). hm Interpret the data presented in phase diagrams. hm Understand the energy content of a chemical reaction. hm nalyze the evidence of chemical change. RELESE hm nalyze the law of conservation of matter and how it applies to various types of chemical equations (synthesis, decomposition, single replacement, double replacement, and combustion). 3

16 HEMISTRY RELESE I TEMS hm nalyze the stoichiometric relationships inherent in a chemical reaction. hm Explain the factors that affect the rate of a reaction (temperature, concentration, particle size and presence of a catalyst). hm Infer the shift in equilibrium when a stress is applied to a chemical system (Le hatelier s Principle). hm lassify substances using the hydronium and hydroxide ion concentrations. hm Summarize the properties of solutions. hm Explain the solution process. RELESE 4