1 ACS Practice Test 1 A D A C B H2O A NH3 donating a pair of electrons 2Na s Cl2 g 2NaCl s C H aq OH aq H2O l B HCl g NH3 g NH4Cl s Cu2 aq 4NH3 aq Cu NH3 4 2 aq B accepting a hydrogen ion having a hydrogen ion accepting a pair of electrons D Acids Bases 1 All are examples of Lewis acid base reactions except 2 According to the Lewis definition an acid is a species 3 All are potential Lewis bases except C 4 Which hydrated metal ion is most acidic under conditions of equal molar concentration in water 5 Which element in Group 5A forms the most basic oxide Atomic Structure 6 In what respect does an atom of magnesium differ from a magnesium ion Mg2 A The ion has a more stable electronic arrangement than the atom B The positive charge on the nucleus of the ion is two units greater than the nuclear charge on the atom C The ion has two more protons than the atom D The ion will react more readily with free Cl2 E The ion has two more planetary electrons than the atom 7 A certain atom has the symbol 148 It has 148 electrons B It has 221 protons in the nucleus Its atomic mass is 73 u 73Px What does this symbol tell about an atom of the element It has a valence of 4 It has 75 neutrons in the nucleus A Al3 C As C K A N CH4 Ba2 Zn2 CN Ag D D D D B B E E Sb Bi P A C E 8 The atomic mass of an element is 32 07 u and its atomic number is 16 The number of protons contained in the nucleus of an atom of this element is D 9 The atomic mass of an element is 32 07 u and its atomic number is 16 The element forms a simple A B C 16 32 31 48 ion The ion will most likely have a charge of 3 A B C 1 2 D 1 UnOfficial ACS Practice Test 1A 10 The nucleus of which atom contains seven neutrons 2 Atom A M 24 Z 12 Atom B M 15 Z 7 Atom C M 17 Z 10 Atom D M 7 Z 3 Atom E M 34 Z 17 A A n 1 2 e n 1 2 e n 1 2 e n 1 2 e n 1 2 e n 2 8 e n 2 5 e n 2 8 e n 2 1 e n 3 2 e n 3 n 3 n 3 n 3 n 2 8 e 7 e C C E B E B B D D D SnF4 CF4 SnI4 SnF4 TlCl TlCl3 C LiF BF3 Bonding 11 In which pair of compounds should the first member be more covalent than the second member A 12 Which is the most complete and best description of a covalent bond A a system of two nuclei with a pair of electrons located exactly midway between both nuclei B the attractive force between two atoms of opposite charge C a donor bond in which one atom donates an unshared pair to the other D a system of two nuclei where each atom donates one electron to the other atom thus forming a bond 13 Which pair of elements is most likely to react to form a covalently bonded species 14 Which chloride should exhibit the most covalent type of bond BaCl2 15 The compound of which two elements is most likely to involve covalent bonding A NaCl B KCl Ca and O C K and S D Zn and C CaCl2 D E BeCl2 P and O A C B Electronegativities of Unknown Elements Q 0 9 R 1 0 T 2 8 X 3 0 Z 4 0 C T and X B R and T A Q and Z Electrochemistry 16 Chromium metal can be plated from an acidic solution of CrO3 D R and X E R and Z CrO3 aq 6H aq 6e Cr s 3H2O How many grams of chromium will be plated by the passage of 19 300 C coulombs A 5 19 10 4 1 73 0 20 D B C UnOfficial ACS Practice Test 1A 17 What time is required to plate 2 08 g of copper at a constant current flow of 1 26 A 3 Cu 63 5 g mol 1 Atomic Molar Mass Cu2 aq 2e Cu s A 18 Nickel is a transition element and has a variable valence Using a nickel salt 2 F faradays plate out 41 8 min 83 6 min 4820 min 128 min D C B 39 2 g of nickel What ions are in the solution of this salt Atomic Molar Mass Ni 58 7 g mol 1 19 A given amount of electric charge deposits 2 159 g of silver from an Ag solution What mass of B Ni2 A Ni D Ni2 3 C Ni3 copper from a Cu2 solution will be deposited by the same quantity of electric charge Atomic Molar Masses Ag Cu 0 635 g 107 9 g mol 1 63 5 g mol 1 B A A 127 g 1 97 g C 2 54 g D Cu2 aq B Ag aq C Hg2 aq 20 If each of these ions were reduced to metal with one coulomb which would yield the greatest mass Equilibrium 21 Which is a proper description of chemical equilibrium A The frequencies of reactant and of product collisions are identical B The concentrations of products and reactants are identical C The velocities of product and reactant molecules are identical D Reactant molecules are forming products as fast as product molecules are reacting to form reactants E The numbers of moles of reactants and products are equal 22 When equilibrium has been reached in the reaction AE CD CE AD x kJ Cu aq D in which all substances are in solution A B C D E adding AE will increase the concentration of CE but not of AD adding CD will increase the concentration of both AE and AD heating will increase the concentration of both AE and CE escape of some AD by volatilization will increase the concentration of CE doubling the pressure will increase the concentration of CE 23 Given the reaction 2X g Y g 2Z g H 335 kJ which combination of pressure and temperature gives the highest yield of Z at equilibrium 500 atm and 500 C 500 atm and 100 C 1000 atm and 500 C 1000 atm and 100 C catalyst 500 atm and 100 C A C E B D UnOfficial ACS Practice Test 1A 24 The reaction for the formation of ammonia by direct combination is N2 3H2 2NH3 H 92 kJ Which operation will increase the yield of ammonia in the equilibrium mixture A C E doubling the concentration of hydrogen raising the temperature adding a catalyst increasing the reaction time D reducing the total pressure B 4 A B C …