9. The ratio of the volume of nitrogen to that of the ammonia in the reaction N2 + 3 H2 2 NH3 is 1) 1:2; 2) 1:3; 3) 3:2; 4) 2:3.

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1 1. In a balanced chemical equation l) coefficients are equal; 2) atoms are conserved; 3) molecules are equal; 4) energy is always produced; 5) none of these. 2. Which of the following statements about a chemical reaction is false? 1) The mass of the reactants consumed equals the mass of the products formed. 2) No atoms are created or destroyed in the reaction. 3) The number of moles of products equals the number of moles of reactants. 4) The reaction produces new molecules through rearrangement of atoms. 3. To satisfy the law of conservation of matter, an equation 1) must be written in words; 2) should show the atomic mass of both reactants and products; 3) must be balanced; 4) must indicate the physical state of each of the reactants and products. 4. The number of atoms of oxygen indicated by the formula Ca3(PO4)2 is: 1) 8; 2) 7; 3) 3; 4) 4; 5) Which of the following expressions represents two molecules of water? 1) H2O 2) H2O2 3) 2 H2O 4) 2 HO2 5) none of these 6. The smallest quantity of an element that can take part in a chemical reaction is called: 1) a molecule; 2) an atom; 3) a block; 4) an angstrom unit. 7. In a balanced equation the numerical coefficients arrived at in balancing the equation are identical with 1) the molar volumes. 3) the number of moles of each substance. 2) the number of gram-atoms. 4) the specific gravity of each gas. 8. The proportion in which elements combine to form a given compound 1) never varies. 3) varies when stirred. 2) varies when heated. 4) varies when mixed explosively. 9. The ratio of the volume of nitrogen to that of the ammonia in the reaction N2 + 3 H2 2 NH3 is 1) 1:2; 2) 1:3; 3) 3:2; 4) 2: The breaking down of a complex substance to form two or more simpler substances is: 1) decomposition; 2) composition; 3) replacement; 4) double replacement. 11. The substances to the left of the arrow in a chemical equation are called 1) coefficients; 2) products; 3) subscripts; 4) reactants. 12. In every balanced equation, one should find represented on both sides the same number of: 1) atoms; 2) coefficients; 3) isotopes; 4) molecules.

2 13. A gas whose molecule is monatomic is 1) oxygen; 2) helium; 3) nitrogen; 4) chlorine; 5) hydrogen. 14. A particle which enters into a chemical reaction is 1) an electron; 2) a proton; 3) a positron; 4) a neutron; 5) all of these. 15. C + O2 CO2 means which of the following? 1) When carbon combines with oxygen, carbon dioxide is formed. 2) Calcium and ozone will form a stable compound. 3) Carbon monoxide is released when gasoline is burned. 4) The air contains two molecules of oxygen and one of carbon. 16. A hypothetical element, Z, forms a chloride with the formula ZC15. What is the most probable formula for its oxide? 1) ZO2 2) ZO5 3) Z2O5 4) Z5O2 17. The smallest particle of an element that can take part in a chemical change is 1) an atom; 2) a neutron; 3) a molecule; 4) an oxide. 18. When a correctly written formula equation, is balanced 1) the total number of atoms on one side must equal the total number of atoms of the other side. 2) the sum of the coefficients on the left side must equal the coefficient sum on the right side. 3) the number of subscripts on each side must be equal. 4) all molecules must be diatomic. 19. Balancing a formula equation is achieved by 1) adjusting the subscripts in the formulas. 2) adjusting the coefficients to the smallest possible whole number ratio. 3) adjusting the number of elements produced. 4) adjusting an incorrect formula of a compound. 20. In balanced equations, both sides always contain the same number of 1) atoms; 2) coefficients; 3) ions; 4) molecules. 21. In a chemical reaction, 1) atoms may be rearranged; 2) atoms may be destroyed; 3) atoms may be created; 4) all atoms become molecules. 22. The total number of atoms represented by the formula K3Fe(CN)6 is 1) 6; 2) 10; 3) 13; 4) 14; 5) A word equation states all of the following except: 1) the substances which enter into the chemical reaction. 2) the substances which are produced by a chemical reaction. 3) the quantities of substances involved. 4) an experimental fact or facts.

3 24. The correct formula for three molecules of oxygen is 1) O3; 2) O2; 3) 3 O2; 4) 3 O; 5) 2 O Of the following words, the one used to represent a chemical reaction is 1) an atom; 2) a formula; 3) an equation; 4) a symbol; 5) a mole. 26. A balanced chemical equation shows that in any chemical reaction, 1) some new atoms may be created. 3) atoms are rearranged. 2) some atoms may be destroyed. 4) the coefficients remain the same. 27. To balance an equation, we use 1) exponents; 2) subscripts; 3) superscripts; 4) coefficients; 5) all of these. 28. The substances to the right of the arrow in a chemical equation are called 1) subscripts; 2) products; 3) coefficients; 4) reactants. 29. The process whereby a chemist produces a new material by combining elements is called 1) hydrolysis; 2) electrolysis; 3) analysis; 4) synthesis. 30. The chemical reaction represented by the equation: 2 NaOH + H2SO4, is an example of 1) double replacement; 2) single replacement; 3) decomposition; 4) direct combination. 31. The reaction between zinc and hydrogen chloride is l) direct composition; 2) single replacement; 3) neutralization; 4) double replacement. 32. The combining of simple substances to form a more complex substance is 1) decomposition; 2) analysis; 3) fission; 4) replacement; 5) composition. 33. The valence number of each element always remains unchanged in 1) composition reactions. 3) single replacement reactions. 2) decomposition reactions. 4) double replacement reactions. 34. The reaction: iron + oxygen iron oxide, is an example of 1) direct composition; 2) decomposition; 3) single replacement; 4) double replacement. 35. The type of reaction represented by the expression + AY + BX is 1) composition; 2) decomposition; 3) replacement; 4) double replacement. 36. An example of a double replacement reaction is 1) 2 HgO 2 Hg + O2. 3) Zn + 2 HC1 ZnCl2 + H2. 2) Al2(SO4)3 + 3 Ca(OH)2 2 Al(OH)3 + 3 CaSO4. 4) 2 H2 + O2 2 H2O. 5) 3 H2 + N2 2 NH3.

4 37. Which of the following represents a single replacement type of reaction? 1) Ni + S NiS 3) CuSO4 + Fe FeSO4 + Cu 2) 2 H2O 2 H2 + O2 4) C + O2 CO2 38. The type of reaction represented by the expression + BZ is a: 1) composition reaction. 3) replacement reaction. 2) decomposition reaction. 4) double replacement reaction. 39.The type of reaction represented by the expression, CT is a 1) composition reaction. 3) replacement reaction. 2) decomposition reaction. 4) double replacement reaction. 5) condensation reaction. 40. The combination of two or more simple substances to form a more complex substance is 1) composition; 2) decomposition; 3) condensation; 4) replacement; 5) double replacement. 41. The type of reaction represented by the generalized form of an equation Y + BX BY + X is a 1) composition reaction; 2) decomposition reaction; 3) replacement reaction; 4) double replacement reaction; 5) condensation reaction. 42. An example of a replacement reaction is: 1) H2O + SO2 H2SO3. 3) Cl2 + 2 KI 2 KC1 + I2. 2) 2 H2 + O2 2 H2O. 4) Fe + S FeS. 43. All of the following reactions belong to one type except 1) 2 NaCl 2 Na + Cl2. 3) Ca(OH)2 CaO + H2O 2) CaCO3.CaO + CO2 4) Zn + H2SO4 ZnSO4 + H The balanced equation for the synthesis of ammonia is 1) N2 + 3 H2 2 NH3 3) 2 N + 3 H2 2 NH3 2) N2O + 3 H2O 2 NH3 + 2 O2 4) 4 NO + 6 H2O 4 NH3 + 5 O2 45. Which set of coefficients correctly balances the reaction K3PO4 + MgCl2? 1) 1, 3, 1, 6 2) 2, 3, 1, 6 3) 2, 3, 2, 1 4) 3, 2, 1, 6 5) none of these 46. The coefficient X which should appear when the following molecular equation, C2H6 + X O2 CO2 + H2O, is correctly balanced is 1) 7; 2) 2; 3) 8; 4) 6; 5) none of these.

5 47. Consider the unbalanced expression: Cu (s) + NO3 - (aq) + H + (aq) Cu +2 (aq) + NO(g) + H2O(l). Which set of coefficients correctly balances the equation? 1) 4,5,3,8,2,3 2) 2,4,3,8,3,3 3) 3,2,8,7,2,4 4) 3,2,8,3,2,4 48. When the equation SbCl3 + H2S Sb2S3 + is balanced, the coefficient of H2S is 1) 4; 2) 2; 3) 5; 4) 6; 5) none of these. 49. When the equation ZnS + O2 ZnO + SO2 is balanced, the coefficient of the reactant O2 will be l) 1; 2) 2; 3) 3; 4) Which of the following sets of coefficients correctly balances the equation: Ca3( PO4)2 + H2SO4 Ca(H2PO4)2 + CaSO4? 1) 1, 1, 1, 1 2) 1, 2, 1, 2 3) 1, 3, 1, 2 4) 1, 1, 3, 2 5) none of these 51. Consider the unbalanced expression: CH3CH2CHO(l) + O2(g) CO2 (g) + H2O(g). Which set of coefficients balances the equation? 1) 2, 8, 3, 6 2) 3, 8, 6, 6 3) 1, 4, 3, 2 4) 1, 8, 3, 3 5) 1, 4, 3, The coefficient X which should appear when the following molecular equation, x HC1 + MnO2 MnCl2 + H2O + Cl2, is balanced correctly is 1) 1; 2) 2; 3) 3; 4) 4; 5) The coefficient X which should appear when the equation, C2H2 + xo2 CO2 + H2O, is balanced correctly is 1) 1; 2) 2; 3) 3; 4) 4; 5) The term X in the correctly balanced equation, 2 H2S + O2 2 H2O + X is 1) 2 H2SO4; 2) 2 S; 3) 2 SO4; 4) 2 SO2; 5) 2 SO Which set of coefficients balances the equation for the complete combustion of ethane? C2H6 + O2 CO2 + H2O 1) 1, 3, 2, 3 2) 1, 6, 2, 6 3) 2, 6, 4, 5 4) 2, 7, 4, 6

6 56. The balanced equation for the single replacement reaction between copper and silver nitrate is 1) Cu + AgNO3 AgCuNO3. 3) Cu + 2 AgNO3 Cu(NO3)2 + 2 Ag. 2) Cu + AgNO3 no reaction. 4) Cu + AgNO3 Ag + + Cu + + NO In the thermite reaction iron is produced from iron ore, Fe3O4. Which expression for this reaction is balanced? 1) Fe3O4 + 2 Al A12O3 + 3 Fe 3) 3 Fe3O4 + 4 A1.4 Al2O3 + 9 Fe 2) 2 Fe3O4 + 2 Al 2 A12O3 + 6 Fe 4) 3 Fe3O4 + 8 A1 4 A12O3 + 9 Fe 58. The coefficient X which should appear when the molecular equation Al + X HC1 +, is correctly balanced is 1) 8; 2) 4; 3) 3; 4) 6; 5) What is the coefficient of P when the expression is balanced? H2SO4 + P H3PO4 + H2O + SO2 1) 1 2) 2 3) 5 4) 4 5) none of these 60. Among the following equations, the one which is correctly balanced is 1) C + O2 CO2. 3) HgO Hg + O2. 2) 2 H2O H2 + O2. 4) 2 Zn + Cl2 ZnCl2 + H2. 5) 2 NH3 N2 + 2 H The expression for pentane, C5H12, burning in oxygen is C5H12(g) + O2(g) CO2(g) + H2O(g). What set of coefficients balances the equation? 1) 1, 8, 5, 6 2) 2, 8, 10, 6 3) 1, 8, 5, 12 4) 1, 11, 5, 12 5) 3, 8, 7, When the equation Cu2S + O2 CuO + SO2 is balanced, the coefficient of the reactant Cu2S will be 1) 1; 2) 2; 3) 3; 4) Among the following equations the one which is correctly balanced is: 1) S + O2 SO2. 3) H2 + O2 H2O. 2) 2 HgO Hg + O2. 4) Zn + HC1 ZnC12 + H Which expression for the complete combustion of pentane, C5H12, is balanced? 1) 2 C5H O2 10 CO H2O 3) C5H O2 5 CO2 + 6 H2O 2) 2 C5H O2 10 CO2 + 6 H2O 4) C5H O2 5 CO H2O

7 65. The coefficient X which should appear when the following molecular equation, SbCl3 + H2S Sb2S3 + X HC1, is balanced correctly is 1) 8; 2) 9; 3) 2; 4) 3; 5) The coefficient X which should appear when the equation, A12(SO4)3 + Ca(OH)2 X CaSO4 +, is balanced correctly is: 1) 1; 2) 2; 3) 3; 4) 4; 5) some other number. 67. Balance the following expression. Select the set of coefficients which corresponds to those in the balanced equation. NH4OH + FeCl3 +. 1) 1, 1, 3, 1 2) 2, 2, 3, 2 3) 3, 1, 3, 1 4) l, 3, 3, 1 5) 2, 3, 2, When the equation Fe + Fe3O4 + H2 is correctly balanced, the coefficient for H2 will be 1) 1; 2) 2; 3) 3; 4) 4; 5) PbO2 + HC1 PbCl2 + Cl2 + H2O. When this reaction is properly balanced with whole number coefficients, the coefficient in front of HC1 is 1) 2; 2) 3; 3) 4; 4) 6; 5) none of these. 70. Which equation is correctly balanced? 1) CaO + 2 H2O Ca(OH)2 3) Ca(OH)2 + 2 H3PO4 Ca3(PO4)2 + 3 H2O 2) NH3 + 2 O2 HNO3 + H2O 4) Cu + H2SO4 CuSO4 + H2O + SO2 71. In the reaction Al + O2, how many moles of aluminum oxide are produced from one mole of aluminum? 1) 0.5 mole 2) 2.0 moles 3) 3.0 moles 4) 4.0 moles 5) none of these 72. In the balanced equation Al2(SO4)3 + Ca(OH)2, the Ca(OH)2 has the coefficient of 1) 1; 2) 2; 3) 3; 4) 4; 5) What is the coefficient of hydrogen sulfide when this equation is balanced? H2S + SO2 S + H2O 1) 1 2) 2 3) 3 4) 4 5) 5

8 74. Consider the equation CH4(g) + 2 O2(g) CO2(g) + 2 H2O(g). The number of atoms of oxygen required to react with 1 molecule of CH4 is 1) 4; 2) 10; 3) 20; 4) Pentane gas, C5H12, is combined with oxygen gas to yield water and carbon dioxide.which set of coefficients balances this equation? 1) 2, 4, 5, 6 2) 1, 8, 6, 5 3) 4, 5, 7, 2 4) 4, 5, 2, 7 5) none of these 76. Which set of coefficients balances this equation? CH4(g) C3H8(g) + H2(g). 1) 3, 1, 1 2) 3, 2, 1 3) 3, 1, 2 4) 6, 2, 2 5) 6, 2, The balanced equation for the commercial production of iron III chloride is 1) 2 Fe + 3 Cl2 2 FeCl3 3) 3 Fe + 2 C12 2 FeC13 2) 3 Fe + 3 C12 2 FeCl3 4) Fe + Cl2 FeC When the equation the CS2 + O2 CO2 is correctly balanced, coefficient in front of O2 will be: 1) 1; 2) 2; 3) 3; 4) The term X in the correctly balanced chemical reaction 2 NaC1O2 + Cl2 2 C1O2 + X, is 1) Na2C12; 2) 2 NaCl; 3) Na2O;.4) 3 NaCl; 5) none of these. 80. Given the unbalanced equation: (NH4)3PO4 + Ba(NO3)2. What is the coefficient in front of ammonium nitrate when the equation is correctly balanced with the smallest whole-number coefficients? 1) 6 2) 2 3) 3 4) 4 5) What is the coefficient of NH4Br in the following equation when it is balanced? Al2(SO4)3 + NH4Br. 1) 2 2) 4 3) 5 4) 6 5) Complete the following reaction: Sodium chlorate + nickel. When the reaction is correctly balanced, what is the coefficient in front of sodium chlorate? 1) 1 2) 2 3) 3 4) 4 5) Complete the reaction: zinc hydrogen carbonate + ammonium phosphate. When this

9 reaction is properly balanced, what is the coefficient in front of zinc hydrogen carbonate? l) 1 2) 2 3) 3 4) 4 5) Complete and balance the reaction: chromium (III) oxide. What is the coefficient in front of chromium (III) oxide? 1) 7 2) 5 3) 4 4) 3 5) Complete and balance the reaction: magnesium + hydrogen phosphate. What is the coefficient in front of magnesium? 1) 6 2) 5 3) 4 4) 3 5) Complete and balance the following reaction. silver sulfate + ferric iodide. What is the coefficient in front of silver sulfate? l) 1 2) 2 3) 3 4) 4 5) Complete and balance the following reaction. aluminum + bromine. What is the coefficient in front of bromine? l) 5 2) 4 3) 3 4) 2 5) What does X stand for in the following balanced chemical reaction? Aluminum sulfate + calcium hydroxide X + calcium sulfate. 1) Al 2) 2 Al 3) Al(OH)3 4) 2 Al(OH)3 5) none of these 89. Complete and balance the following chemical reaction: X + oxygen aluminum oxide. What is represented by X in this reaction? 1) 4 Al 2) X2O 3) Al 4) Al3O2 5) none of these 90. What does X stand for in the following balanced chemical reaction? Zinc + X zinc sulfate + hydrogen. 1) H2 2) H2O 3) SO2 4) H2SO4 5) none of these

10 91. When this reaction is properly balanced, what is the coefficient in front of aluminum? Aluminum + zinc hydrogen carbonate. 1) 1 2) 2 3) 3 4) 4 5) When the following reaction is correctly balanced, identify the coefficient in front of ammonium sulfide. Calcium phosphate + ammonium sulfate 1) 1 2) 2 3) 3 4) 4 5) Complete and balance the following chemical reaction. Copper (II) sulfate + iron (III) hydroxide. What is number in front of copper(ii)sulfate? l) 1 2) 2 3) 3 4) 5 5) Complete and balance the following chemical reaction. magnesium phosphate + hydrogen. What is the coefficient in front of magnesium phosphate? l) 1 2) 2 3) 3 4) 4 5) Balance the equation: Zn3As2 reacts with hydrogen chloride to produce AsH3 and zinc chloride. What is the coefficient in front of hydrogen chloride? 1) 7 2) 6 3) 5 4) 4 5) Balance the equation: potassium hydroxide + aluminum hydroxide yield K3AlO3 and water. What is the coefficient in front of water? 1) 7 2) 5 3) 4 4) 3 5) none of these 97. When the following chemical reaction is balanced with lowest coefficients, what is the sum of these coefficients? HC1 + Zn3As2 1) 6 2) 11 3) 12 4) 14 5) This is a complete combustion reaction. Balance and get the sum of the coefficients in this equation: C3H4 + oxygen. 1) 8 2) 9 3) 10 4) 11 5) 14

11 99. If nitrogen gas reacts with lithium to produce only lithium nitride, Li3N, the sum of the coefficients in the balanced equation is: 1) 5; 2) 6; 3) 7; 4) 8; 5) What is the sum of the coefficients in the following reaction after it is balanced? iron III nitrate + sodium sulfide. 1) 8 2) 11 3) 12 4) 13 5) none of these 101. Balance the half reaction below and then determine the sum of its coefficients. ferric phosphate + chromium. 1) 4 2) 5 3) 6 4) 7 5) The sum of the coefficients for the equation + H2SO4 Al2SO4 + H2 should be 1) 9; 2) 7; 3) 11; 4) 8; 5) Starting with one mole of FeCl3, what is the sum of the coefficients in the balanced equation FeC13 + KOH? 1) 4 2) 6 3) 8 4) 11 5) Complete the following reaction. Balance it. Then, add up the coefficients. What is your total? Chromium + bromine. 1) 3 2) 5 3) 6 4) 7 5) none of these 105. This is a complete combustion reaction. Balance and find the sum of the coefficients in this equation. C3H8 + oxygen. 1) 9 2) 13 3) 15 4) 16 5) none of these 106. What is the sum of the coefficients in the following equation after it is balanced? diphosphorus pentoxide. 1) 5 2) 7 3) 8 4) 9 5) Balance the half-reaction and then determine the sum of its coefficients.

12 magnesium oxide + aluminum. 1) 9 2) 8 3) 7 4) 5 5) none of these 108. When this equation is balanced, add up the coefficients. What is this total? aluminum + hydrogen iodide. 1) 7 2) 13 3) 16 4) 21 5) none of these 109. Fluorine reacts with sodium hydroxide to form sodium fluoride, oxygen and water. What is the sum of the coefficients in the balanced equation? 1) 13 2) 17 3) 19 4) 21 5) Complete combustion of any hydrocarbon in air produces 1) CO and H2; 2) CO and H2O; 3) CO2 and H2; 4) CO2 and H2O When coal is burned completely, it yields: 1) carbon and sulfuric acid; 2) carbon dioxide and water; 3) carbon monoxide and lead; 4) carbon and heavy water The complete combustion of ethane, C2H6, produces 1) C2H5OH; 2) CH3COOH; 3) CO2 and H2; 4) CO2 and H2O C2H6 + O2 yield. When the reaction is completed and balanced with whole numbered coefficients, the coefficient in the front of O2 (assume complete combustion) is: 1) 2; 2) 3; 3) 5; 4) How many moles of water are formed when one mole of butane, C4H10 (g), is burned in oxygen? 1) 1 mole 2) 5 moles 3) 8 moles 4) 11.2 moles 5) 22.4 moles 115. Write the balanced equation for the complete combustion of benzene, C6H6, in oxygen. What is the whole-numbered coefficient in front of oxygen? 1) 2 2) 6 3) 12 4) 13 5) One mole of substance X reacts with one mole of water and produces one mole of oxygen and two moles of hydrogen fluoride. X + H2O O2 + 2 HF. Which is the formula for substance X? 1) F2 2) OF2 3) O2F 4) HOF When 40 grams of mercury are heated with oxygen, the mercury unites with 3 grams of oxygen to form 43 grams of mercuric oxide. This reaction illustrates

13 1) the fact that elements always combine. 3) the Law of Conservation of Matter. 2) a nuclear transformation. 4) the formation of mixtures Consider the reaction CH4 + O2 CO2 + H2O. The number of grams of water formed when 32 grams of methane are burned is: 1) 20 grams; 2) 36grams; 3) 45grams; 4) 72grams.