(B) K2O potassium dioxide

Transcription

1 PRACTICE CHEMISTRY EOC TEST 1. Which substance is a conductor of electricity? (A) NaCl(s) (B) NaCl(l) (C) C6H12O6(s) (D) C6H12O6(l) 2. Which formula is correctly paired with its name? (A) MgCl2 magnesium chlorine (B) K2O potassium dioxide (C) CoCl2 copper (II) chloride (D) FeO iron (II) oxide 3. What is the molarity of a KF(aq) solution containing 116 grams of KF in 1.00 liter of solution? (A) 1.00 M (B) 2.00 M (C) 3.00 M (D) 4.00 M 4. Which compound has the LEAST ionic character? (A) KCl (B) AlCl3 (C) CCl4 (D) CaCl2 5. Which is the electron configuration of an atom of a Period 3 element? (A) 1s 2 2s 1 (B) 1s 2 2s 2 2p 3 (C) 1s 2 2p 1 (D) 1s 2 2s 2 2p 6 3s 1 6. Which of the following elements has the largest atomic radius? (A) strontium (B) tin (C) rubidium (D) iodine 7. At STP, 32.0 liters of O2 contain the same number of molecules as (A) 22.4 liters of Ar (B) 32.0 liters of H2 (C) 28.0 liters of N2 (D) 44.8 liters of He 8. When a metal reacts with a nonmetal, the metal will (A) lose electrons and form a positive ion (B) lose protons and form a positive ion (C) gain electrons and form a negative ion (D) gain protons and form a negative ion 9. According to the Arrhenius theory, a substance that is classified as an acid will always yield (A) H +1 (aq) (B) OH -1 (aq) (C) NH4 +1 (aq) (D) CO3-2 (aq) 10. What is the net ionic equation for a neutralization reaction? (A) H +1 + H2O H3O +1 (B) H +1 + NH3 NH4 +1 (C) 2 H O -2 2 OH -1 (D) H +1 + OH -1 H2O 11. The oxidation number of nitrogen in N2O is (A) +1 (B) +2 (C) 1 (D) How many milliliters of 4.00 M NaOH are required to exactly neutralize 50.0 milliliters of a 2.00 M solution of HNO3? (A) 25.0 ml (B) 100. ml (C) 50.0 ml (D) 200. ml 13. Why is salt (NaCl) put on icy roads and sidewalks in the winter? (A) It is ionic and lowers the freezing point of water. (B) It is ionic and raises the freezing point of water. (C) It is covalent and lowers the freezing point of water. (D) It is covalent and raises the freezing point of water. 14. Which gas diffuses most rapidly at STP? (A) Ar (B) Kr (C) O2 (D) N2 15. Which formulas represent a conjugate acid-base pair? (A) CH3COOH and CH3COO -1 (B) H3O +1 and OH -1 (C) H2SO4 and SO4-2 (D) H3PO4 and PO4-3

2 16. Which group below contains elements with the greatest variation in chemical properties? (A) Li, Be, B (B) B, Al, Ga (C) Li, Na, K (D) Be, Mg, Ca 17. What is the total number of electrons in a Mg +2 ion? (A) 2 (B) 10 (C) 12 (D) Which is a molecular substance? (A) CO2 (B) KCl (C) KClO3 (D) CaO 19. Which reaction system s entropy DECREASES as reactants form products? (A) C(s) + O2(g) CO2(g) (B) S(s) + O2(g) SO2(g) (C) I2(s) + Cl2(g) 2 ICl(g) (D) 2 Mg(s) + O2(g) 2 MgO(s) 20. Which substance CANNOT be decomposed by a chemical change? (A) ammonia (B) methane (C) water (D) carbon 21. Given the equilibrium system at 25 o C: NH4Cl(s) NH4 +1 (aq) + Cl -1 (aq) (ΔH = kcal/mole) Which change will shift the equilibrium to the right? (A) decreasing the temperature to 15 o C (B) increasing the temperature to 35 o C (C) dissolving NaCl crystals in the equilibrium mixture (D) dissolving NH4NO3 crystals in the equilibrium mixture 22. Which ion has the electron configuration of a noble gas? (A) Cu +2 (B) Ca +2 (C) Hg +2 (D) Fe Which phase change results in a release of energy? (A) Br2(l) Br2(s) (B) H2O(s) H2O(l) (C) I2(s) I2(g) (D) NH3(l) NH3(g) 24. As HCl (aq) is added to a basic solution, the ph of the solution will (A) decrease (B) increase (C) remain the same 25. A property of most nonmetals in the solid state is that they are (A) good conductors of heat (B) good conductors of electricity (C) brittle (D) malleable 26. What is the mass in grams of 3.0 x molecules of CO2? (A) 22 g (B) 44 g (C) 66 g (D) 88 g 27. An atom of an element has the electron configuration 1s 2 2s 2 2p 2. What is the total number of valence electrons in this atom? (A) 6 (B) 2 (C) 5 (D) Given the reaction: 2 PbO 2 Pb + O2 What is the total volume of O2, measured at STP, produced when 1.00 mole of PbO decomposes? (A) 5.60 L (B) 22.4 L (C) 11.2 L (D) 44.8 L 29. Given the nuclear equation: 9 4Be + X 6 3Li + 4 2He What is the identity of particle X in this equation? (A) 1 1H (B) 1 0n (C) 0-1e (D) 2 1H

3 30. Which atoms contain the same number of neutrons? (A) 1 1H and 3 2He (B) 3 1H and 3 2He (C) 2 1H and 4 2He (D) 3 1H and 4 2He 31. Which atom contains exactly 15 protons? (A) phosphorus-32 (B) oxygen-15 (C) sulfur-32 (D) nitrogen Which is a correctly balanced equation for a reaction between hydrogen gas and oxygen gas? (A) H2(g) + O2(g) H2O(l) + heat (B) H2(g) + O2(g) 2 H2O(l) + heat (C) 2 H2(g) + 2 O2(g) H2O(l) + heat (D) 2 H2(g) + O2(g) 2 H2O(l) + heat 33. The atom of which element has an ionic radius smaller than its atomic radius? (A) N (B) S (C) Br (D) Rb 34. Atoms of elements in a group on the Periodic Table have similar chemical properties. This similarity is most closely related to the atoms' (A) number of principal energy levels (B) number of valence electrons (C) atomic numbers (D) atomic masses 35. Which element in Period 2 of the Periodic Table is the most reactive nonmetal? (A) fluorine (B) oxygen (C) beryllium (D) lithium 36. Given the reaction: Ca(s) + 2 H2O(l) Ca(OH)2(aq) + H2(g) When 40.1 grams of Ca(s) react completely with the water, what is the total volume, at STP, of H2(g) produced? (A) 1.00 L (B) 2.00 L (C) 22.4 L (D) 44.8 L 37. As atoms of elements in Group 16 are considered in order from top to bottom, the electronegativity of each successive element (A) decreases (B) increases (C) remains the same 38. Given the change of phase CO2(g) CO2(s) As CO2(g) changes to CO2(s), the entropy of the system (A) decreases (B) increases (C) remains the same 39. Electron X can change to a higher or a lower energy level. Which statement is true of electron X? (A) Electron X emits energy when it changes to a higher energy level. (B) Electron X absorbs energy when it changes to a higher energy level. (C) Electron X absorbs energy when it changes to a lower energy level. (D) Electron X neither emits nor absorbs energy when it changes energy level. 40. The oxide of metal X has the formula X2O. Which group in the Periodic Table contains metal X? (A) Group 1 (B) Group 13 (C) Group 17 (D) Group A student determined the heat of fusion of water to be 88 calories per gram. If the accepted value is 80. calories per gram, what is the student s percent error? (A) 8.0% (B) 10.% (C) 11% (D) 90.% 42. What is the empirical formula of a compound that contains 85% Ag and 15% F by mass? (A) AgF (B) Ag2F (C) AgF2 (D) Ag2F2

4 Base your answer to questions 43 and 44 on the table below, which represents the production of 50 milliliters of CO2 in the reaction of HCl and NaHCO3. Five trials were performed under different conditions as shown. (The same mass of NaHCO3 was used in each trial.) Trial Particle Size of NaHCO3 Concentration of HCl Temperature of HCl ( o C) A Small 1 M 20 B Large 1 M 20 C Large 1 M 40 D Small 2 M 40 E Large 2 M Which two trials could be used to measure the effect of surface area? (A) trials A and B (B) trials A and D (C) trials A and C (D) trials B and D 44. Which trial would produce the fastest reaction? (A) trial A (B) trial E (C) trial C (D) trial D 45. The graph below represents the uniform cooling of a sample of a substance, starting with the substance as a gas above its boiling point. Which segment of the curve represents a time when both the liquid and the solid phases are present? (A) EF (B) CD (C) BC (D) DE 46. Which element in Group 15 would most likely have luster and good electrical conductivity? (A) N (B) P (C) Bi (D) As 47. The potential energy diagram below shows the reaction X + Y Z When a catalyst is added to the reaction, it will change the value of (A) 1 and 2 (B) 2 and 3 (C) 1 and 3 (D) 3 and 4

5 48. As the temperature of a given sample of a gas is increased at constant pressure, the volume of the gas will (A) decrease (B) increase (C) remain the same 49. Given the electron dot formula: The attraction for the bonding electrons would be the greatest when X represents an atom of (A) S (B) O (C) Se (D) Te 50. Which is a property of a reaction that has reached equilibrium? (A) The amount of products is greater than the amount of reactants. (B) The amount of products is equal to the amount of reactants. (C) The rate of the forward reaction is greater than the rate of the reverse reaction. (D) The rate of the forward reaction is equal to the rate of the reverse reaction. 51. Which procedure will increase the solubility of KCl in water? (A) stirring the solute and solvent mixture (B) increasing the surface area of the solute (C) raising the temperature of the solvent (D) increasing the pressure on the surface of the solvent 52. Which reaction best illustrates amphoterism? (A) H2O + HCl H3O +1 + Cl -1 (B) NH3 + H2O NH OH -1 (C) H2O + H2SO4 H3O +1 + HSO4-1 (D) H2O + H2O H3O +1 + OH The bond between hydrogen and oxygen in a water molecule is classified as (A) ionic and nonpolar (B) ionic and polar (C) covalent and nonpolar (D) covalent and polar 54. What is the oxidation number of carbon in NaHCO3? (A) +6 (B) 4 (C) +2 (D) The conjugate acid of the HS -1 ion is (A) H +1 (B) H2O (C) S -2 (D) H2S 56. In an aqueous solution of an ionic salt, the oxygen atom of the water molecule is attracted to the (A) negative ion of the salt, due to oxygen s partial positive charge (B) negative ion of the salt, due to oxygen s partial negative charge (C) positive ion of the salt, due to oxygen s partial positive charge (D) positive ion of the salt, due to oxygen s partial negative charge 57. Given the reaction at equilibrium: N2(g) + O2(g) 2 NO(g) As the concentration of N2(g) increases, the concentration of O2(g) will (A) decrease (B) increase (C) remain the same 58. As the elements in Group 2 are considered in order of increasing atomic number, the atomic radius of each successive element increases. This increase is primarily due to an increase in the number of (A) occupied energy levels (B) electrons in the outermost energy level (C) neutrons in the nucleus (D) unpaired electrons 59. What is the correct equilibrium expression for the reaction 2 A(g) + 3 B(g) C(g) + 3 D(g)? (A) K = [2 A] + [3 B] (B) K = [A] 2 [B] 3 [C] + [3 D] [C] [D] 3 (C) K = [C] + [3 D] (D) K = [C] [D] 3 [2 A] + [3 B] [A] 2 [B] 3

6 60. Which reactant is most likely to have d electrons involved in a chemical reaction? (A) a halogen (B) a noble gas (C) a transition metal (D) an alkali metal 61. A real gas would behave most like an ideal gas under conditions of (A) low pressure and low temperature (B) low pressure and high temperature (C) high pressure and low temperature (D) high pressure and high temperature 62. A student observed the following reaction: AlCl3(aq) + 3 NaOH(aq) Al(OH)3(s) + 3 NaCl(aq) After the products were filtered, which substance remained on the filter paper? (A) NaCl (B) AlCl3 (C) NaOH (D) Al(OH)3 63. In which reaction is water acting only as a Bronsted-Lowry base? (A) H2SO4(aq) + H2O(l) HSO4-1 (aq) + H3O +1 (aq) (B) NH3(g) + H2O(l) NH4 +1 (aq) + OH -1 (aq) (C) CH3COO -1 (aq) + H2O(l) CH3COOH(aq) + OH -1 (aq) (D) H2O(l) + H2O(l) H3O +1 (aq) + OH -1 (aq) 64. Which type of reaction occurs when 50 milliliter quantities of Ba(OH)2(aq) and H2SO4(aq) are combined? (A) reduction (B) oxidation (C) ionization (D) neutralization 65. The table below shows the data collected by a student as heat was applied at a constant rate to a solid below its freezing point. Time (min) Temperature ( o C) Time (min) Temperature ( o C) What is the boiling point of this substance? (A) 32 o C (B) 62 o C (C) 54 o C (D) 100 o C 66. Which of the following species CANNOT act as both a Bronsted-Lowry acid and base? (A) HSO3-1 (B) HS -1 (C) H2O (D) CN Which of the following is the correct ground state electron configuration of gallium (Ga)? (A) [Ar] 4s 2 4d 10 5p 1 (B) [Kr] 4s 2 3d 10 4p 1 (C) [Kr] 5s 2 5d 10 5p 1 (D) [Ar] 4s 2 3d 10 4p What is the total number of valence electrons for a molecule of PH3? (A) 8 (B) 10 (C) 18 (D) Which of the following molecules is polar? (A) HCl (B) CO2 (C) BCl3 (D) CH4 70. The most reactive metals on the Periodic Table have (A) large radii and high electronegativities (C) small radii and high electronegativities (B) large radii and low electronegativities (D) small radii and low electronegativities

7 71. What type of forces must be overcome when liquid ammonia vaporizes? 1. covalent bonds 2. London dispersion forces 3. hydrogen bonds (A) 1 only (B) 2 only (C) 2 and 3 only (D) 1, 2, and Fe3O4(s) + 4 H2(g) 3 Fe(s) + 4 H2O(g) (ΔH > 0) For this reaction at equilibrium, which change(s) will increase the quantity of Fe(s)? 1. increasing temperature 2. decreasing pressure 3. adding Fe3O4(s) (A) 1 only (B) 1 and 2 only (C) 2 and 3 only (D) 1, 2, and As ice cools from 273 K to 263 K, the average kinetic energy of its molecules will (A) increase (B) decrease (C) remain the same 74. Which statement describes characteristics of an endothermic reaction? (A) The sign of ΔH is positive, and the products have less potential energy than the reactants. (B) The sign of ΔH is positive, and the products have more potential energy than the reactants. (C) The sign of ΔH is negative, and the products have less potential energy than the reactants. (D) The sign of ΔH is negative, and the products have more potential energy than the reactants. 75. The ability to conduct electricity in the solid state is a characteristic of metallic bonding. This characteristic is best explained by the presence of (A) high ionization energies (B) high electronegativities (C) mobile electrons (D) mobile protons 76. The table below shows the temperature, pressure, and volume of five samples. Sample Substance Temp. (K) Pressure (atm) Volume (L) A He B O C Ne D N E Ar Which sample contains the same number of molecules as sample A? (A) E (B) B (C) C (D) D 77. The characteristic bright-line spectrum of an element is produced when its electrons (A) form a covalent bond (B) form an ionic bond (C) move to a higher energy level (D) return to a lower energy level