Chemistry Released 2498 - MS. MORRISSEY CHEMISTRY

Student Name:RELEASEDChemistry2018–2019Public Schools of North CarolinaDepartment of Public Instruction State Board of EducationDivision of Accountability Services/North Carolina Testing ProgramCopyright ã 2018 by the North Carolina Department of Public Instruction. All rights reserved.NC Final ExamReleased Items

CHEMISTRY — RELEASED ITEMSPa-238BU-240CNp-238DPu-2394B6C11D16SEADA neutral atom of a certain element has the electron configuration1s22s22p63s23p4. How many valence electrons does the atom have?EA3AWhat color of light does a hydrogen atom emit when an electron transitions fromthe n 6 energy level to the n 2 energy level?EL2Which isotope has the greatest number of protons?AorangeByellowCblueDvioletR11Go to the next page.

CHEMISTRY — RELEASED ITEMS4The equation below represents the radioactive decay of a gold isotope.17479Au 17077Ir ?Which choice correctly completes this equation?alpha particleBbeta particleCphotonDneutron2 B1 C2–D6–EAAEL6A neutral atom has a ground state electron configuration of 1s22s22p63s2.The neutral atom becomes an ion during a chemical reaction. Which is themost likely charge of the ion?How many electrons are in the outermost energy level of a neutral carbon atom?R5SEDAA2B4C6D82Go to the next page.

CHEMISTRY — RELEASED ITEMSThe chloride and sodium ions are cations.BThe chloride and sodium ions are anions.CThe sodium ion is the anion, and the chloride ion is the cation.DThe sodium ion is the cation, and the chloride ion is the anion.AcarbonBaluminumCmagnesiumDpotassiumSEDWhich element will form covalent bonds with chlorine?EA9AWhich type of bonding or intermolecular forces is/are weakest?EL8The compound sodium chloride is placed in water and separates into ions. Whatare the correct names for these ions?ALondon dispersion forcesBhydrogen bondingCdipole-dipole forcesDcovalent bondingR73Go to the next page.

CHEMISTRY — RELEASED ITEMSACrOBCrO2CCr2O3DCr3O2Melting Point801 CElectricalConductivity(molten state)35.7EASolubility in Water(grams per 100.0grams of water)Solid YSESolid XDTest results on two white crystalline solids are shown in the table below:good conductor186 C3.2nonconductorEL11What is the chemical formula for chromium(III) oxide?Based on the information in the table, what can be concluded?ABoth solids contain only ionic bonds.BBoth solids contain only covalent bonds.CSolid X contains only covalent bonds, and Solid Y contains only ionic bonds.DSolid X contains only ionic bonds, and Solid Y contains only covalent bonds.R104Go to the next page.

CHEMISTRY — RELEASED ITEMSfluorocobaltBcobalt trifluorideCcobalt(III) fluorideDfluorine(III) cobaltDWhich statement best compares how bond strengths affect the physical propertiesof iron and lead?Iron has a higher melting point because the bonds in iron are stronger.BIron has a higher melting point because the bonds in iron are weaker.CLead has a higher density because the bonds in lead are stronger.DLead has a higher density because the bonds in lead are weaker.SEAEA14AHow is copper (Cu) classified based on its location on the periodic table?EL13What is the name of the compound with the chemical formula CoF3?Aa nonmetalBan alkaline earth metalCa transition metalDan alkali metalR125Go to the next page.

CHEMISTRY — RELEASED ITEMS15The table below shows the electron configurations of three elements.ElementElectronConfigurationElement 11s22s22p2Element 21s22s22p5Element 31s22s22p417BElement 1, Element 3, Element 2CElement 2, Element 1, Element 3DElement 2, Element 3, Element 1EASEElement 1, Element 2, Element 3Which three elements are arranged according to increasing electronegativityvalues?N, C, BBN, P, AsCN, O, FDF, O, NELAR16ADWhat is the order of the elements from smallest to largest atomic radius?Which group of elements is arranged in order of increasing atomic radii?AO, S, Se, TeBFe, Ni, Ag, AuCRb, K, Na, LiDY, Zr, Nb, Mo6Go to the next page.

CHEMISTRY — RELEASED ITEMSAThe rate of vaporization equals the rate of condensation.BThe rate of vaporization is greater than the rate of condensation.CThe rate of vaporization equals the rate of sublimation.DThe rate of vaporization is greater than the rate of sublimation.SEDA phase diagram is shown below.XEL1.0EA2.0Pressure (atm)19Which statement describes equilibrium between liquid water and water vapor?R1801030507090110Temperature ( C)Which choice describes the state of the substance at X?AA boiling liquid is in equilibrium with its vapor.BA subliming solid is in equilibrium with its vapor.CA freezing liquid is in equilibrium with its solid.DA melting solid is in equilibrium with its liquid.7Go to the next page.

CHEMISTRY — RELEASED ITEMSAironBgoldCcopperDmagnesiuma 3.0-liter containerBa 6.0-liter containerCa 9.0-liter containerDa 12.0-liter containerEAASEDA 2.0-liter closed container holds 1.0 mole of an ideal gas at a certain temperatureand pressure. Which closed container will hold 3.0 moles of this ideal gas at thesame temperature and pressure?EL21A sample of metal has a mass of 5.2 g and absorbs 20.0 J of energy as it is heatedfrom 30.0 C to 40.0 C. What is the identity of the metal?R208Go to the next page.

CHEMISTRY — RELEASED ITEMSA phase diagram is shown below.SEDX101.3RELEAPressure (kPa)220100374Temperature ( C)What is the condition of the sample at point X?AThe sample is in a gaseous state.BThe sample is in a liquid state.CThe sample is at its critical point.DThe sample is at its triple point.9Go to the next page.

CHEMISTRY — RELEASED ITEMSWhat is the approximate temperature of 1.4 moles of a gas with a pressure of3.25 atmospheres in a 4.738-liter container?180 KB170 KC150 KD130 KELEASEDAR2310Go to the next page.

CHEMISTRY — RELEASED ITEMSA potential energy diagram of a chemical reaction is shown below.Potential Energyof a Chemical ReactionD8U6SEST4EAPotential Energy (J)10ELR05101520Reaction CoordinateR24Which choice would be changed by the addition of a catalyst to the reaction?ARBSCTDU11Go to the next page.

CHEMISTRY — RELEASED ITEMS25A student conducts the following demonstration: A 15-g sample of NaHCO3 is placed in a test tube. The bottom of the test tube is heated with an open flame. Condensation forms on the inside walls of the test tube. A burning splint is extinguished when placed at the mouth of the testtube.What can the student conclude after conducting this demonstration?BThe burning splint was extinguished because of a lack of H2O vapor.CDecomposition produced CO2 and H2O.DCombustion produced O2 and H2O.EASEDThe burning splint was extinguished because of a lack of CO2 in thetest tube.A chemical equation is shown below.ELCaSO4 AlBr3 CaBr2 Al2(SO4)3What will be the coefficient of CaBr2 when the equation is balanced using thesmallest possible whole-number coefficients?A2B3C4D5R26A12Go to the next page.

CHEMISTRY — RELEASED ITEMS27The equation below represents a chemical reaction.Zn (s) 2HCl (aq) ZnCl2 (aq) H2 (g)B0.0771 gC0.121 gD0.154 gSE0.0308 gCH2OBC2H4O2CC2H4O4DC2H2O2ELAEAWhat is the molecular formula of a compound with the empirical formula CH2O anda molecular mass of 60 g/mol?R28ADA 5.00-g sample of zinc is added to hydrochloric acid. The amount of hydrochloricacid is sufficient to allow the zinc to react completely. What mass of hydrogen gasdoes this reaction produce?13Go to the next page.

CHEMISTRY — RELEASED ITEMS29A student experimented with magnesium ribbon and hydrochloric acid. The student placed a piece of solid magnesium ribbon in a test tubecontaining hydrochloric acid solution. The student observed that vigorous bubbling occurred. The student collected some of the gas generated by the bubbles in atest tube. The student tested the gas produced with a burning wood splint, whichignited quickly with a popping sound.A chemical reaction occurred because new atoms were created.BA chemical reaction occurred because a new substance was formed.CThe popping sound provided evidence that the acid changed physical states.DThe popping sound provided evidence that the magnesium atoms weredestroyed.EASEAELHow many O2 particles are in 2.50 moles of O2 at Standard Temperature andPressure (STP)?A4.15 1022 particlesB2.41 1023 particlesC5.02 1023 particlesD1.51 1024 particlesR30DWhat can the student conclude about the experiment?14Go to the next page.

CHEMISTRY — RELEASED ITEMSbecause the activation energy of the reaction increasesBbecause the surface area of reacting particles increasesCbecause the proper orientation of reacting particles improvesDbecause the number of effective collisions between reacting particlesincreasesDASEThe chemical equation below represents a reaction at equilibrium in a closed flask.Which action will cause the reaction to shift to the left?heating the flask with a hot plateBplacing the flask in an ice bathCremoving H2O from the flaskDadding CO to the flaskEAAEL32Why does an increase in temperature usually increase the rate of a chemicalreaction?R3115Go to the next page.

CHEMISTRY — RELEASED ITEMSIn a hypothetical reaction, reactants X and Y are combined in an evacuated vesseland allowed to come to equilibrium with product Z at a temperature of 200K.X (g) Y (g) Z (g)After equilibrium is established, the temperature is slowly raised, and additionalvalues of Keq are determined as shown in this data table:TemperatureKeq3 10-2300K1 10-2D200K400K5 10-4SE500K4 10-3200KB300KC400KD500KELAEAWhich temperature has the greatest concentration of product Z?R3316Go to the next page.

CHEMISTRY — RELEASED ITEMS34An equilibrium is established between substances W, X, Y, and Z.W X Y ZHow would the conditions of equilibrium be affected by decreasing theconcentration of substance W?36BSubstances Y and Z would react to replace substance W, and the position ofequilibrium would shift to the left.CThis would increase pressure, causing only substance Y to replace substanceW and shifting the equilibrium to the right.DThis would decrease temperature, causing only substance Z to replacesubstance W and shifting the equilibrium to the left.EASEDSubstances X and Y would react to replace substance W, and the position ofequilibrium would shift to the right.A solution has a pOH of 12. Which best describes the solution?It has a pH of 2 and is a base.BIt has a pH of 12 and is a base.CIt has a pH of 2 and is an acid.DIt has a pH of 12 and is an acid.ELAR35AA student describes a liquid as feeling slippery. The student places red litmuspaper into the liquid, and the paper turns blue. What can the student concludefrom these observations?AThe substance is likely a nonmetal.BThe substance is likely a metal.CThe substance is likely a base.DThe substance is likely an acid.17Go to the next page.

CHEMISTRY — RELEASED ITEMS37An acid-base titration is represented by the chemical equation below.CsOH (aq) HBr (aq) CsBr (aq) H2O (l)B0.637 MC1.36 MD10.2 MSE0.0982 MWhat type of solution is formed when solid sodium hydroxide (NaOH) is dissolvedin water?an electrolytic solution, because NaOH will dissociate into ionsBan electrolytic solution, because NaOH will not dissociate into ionsCa nonelectrolytic solution, because NaOH will dissociate into ionsDa nonelectrolytic solution, because NaOH will not dissociate into ionsELEAAR38ADIn the titration, 15.0 mL of CsOH solution is neutralized by 38.2 mLof 0.250 M HBr solution. What is the molarity of the CsOH solution?18Go to the next page.

CHEMISTRY — RELEASED ITEMSThe diagram below shows the solubility of sugar in water.Solubility lity (in g/100 g of water)4060T emperature ( C)80100EL20A student dissolves 300 g of sugar in 100 g of water at 80 C. The solution is thenallowed to cool to 40 C. The appearance of the solution does not change duringthe cooling. Which term accurately describes the solution at 40 d19Go to the next page.