CHEM 101 Final, Fall 1998

Time: 1060 min. Chemistry 161 February 2, 1999 Final Examination Name: Student Number: Signature: Circle one: Sects. 1, 2,3, 7 Prof. Kortz Sects. 4, 5, 6,8 Prof. Sultan instructions: - There are 50 multiple-choice type questions and only ONE of the proposed answers is correct. Circle the letter corresponding to the right answer. No penalty for wrong answers. Tables of atomic numbers and molar masses of the elements provided Pencil and red pen will not be graded Do not detach any pages Constants: Gas constant. R = 8.314 J K™ mol“! = 0.0821 L atm K"! mol’ Planck’s constant, h = 6.626 x 10°" Js Speed of light, c = 2.998 x 10° ms" Rydberg constant, Ry = 109678 em! = 2.18 x 107° J Electron mass, Me = 9.11 x 107! kg Electron charge,e = 1.60 x 10% C | atm = 760 mmHg Avogadro's number, Na = 6.022 x 1073 molec mol! Activity series: Li The Lewis structure for the chlorate ion (C1O;) should show __ single bond(s). double bond(s) and lone pairs. or Wweiv > Avogadro's Law relates the number of molecules of a gas to its a. pressure b. temperature c. molar mass d. volume The electron dot formula for O2 shows: a single covaleut buud a double covalent bond an ionic bond a total of 16 electron dots a total of 32 electron dots Which of the following covalent bonds is the least polar? a. C-Cl C-C C-H O-C N-C The interaction between Ba and Cl in BaCl; is through a(n) bond. a. single, nonpolar covalent ionic double, polar covalent single, polar covalent double, nonpolar covalent Which answer does not belong? The atomic number of an element a. corresponds to the number of protons in the element identifies the order in which the element was discovered is always an integer corresponds to the number of electrons in the element plus the number of neutrons gives the mass number of the element The peroxide ion (O27) has a. adouble bond a triple bond six lone pairs two resonance structures a polar covalent bond Which molecule has a Lewis structure that does not obey the octet rule? N20 C82 PH; CCl NO: Which one of the following molecules has an atom with an incomplete octet? a. NF3 H20 AsCly GeF4 BF; Which one of the following molecules has an atom with an expanded octet? HCl AsCls IC] NC] Ch Within each of the following species all bonds are equivalent. Which one requires two resonance structures? CO CINO2 H20 CHa HS What is the formal charge on the oxygen atom in N20. which has two double bonds? 0 +} -1 Which of the following is a useful guideline for neutral covalent molecules: a. Lewis structures with large formal charges are preferred b. the preferred Lewis structure is one in which positive formal charges are on the most electronegative atoms 4 Lewis structure in which there are no formal charges is preferred the preferred Lewis structure is one in which negative formal charges are on the least electronegative atoms ¢ The bond angle in the molecule Cl20 is expected to be closest to a. 90° b. 109 ° c, 120° d. 145° e. 180° e Which of the following molecules is nonpolar? b. OF2 c. CH3Cl d. H2,0 e. BeCl, e “No two electrons in an atom can have the same four quantum numbers” is a statement called a. the Pauli exclusion principle b. Bohr’s equation c. Hund’s rule d. DeBroglie’s relation e. Dalton’s atomic theory ¢ Calculate the frequency of the light absorbed by a hydrogen atom during a transition of its electron from the n=3 to the n=6 principal energy level. a. 1.64 10's" b. 9.13 x 10% s! ¢. 3.65 x 10's! d. 1.82 x 10°77 s" e. 2.70 x 10's" e A5.0 liter tank was filled with 46 liters of O2 (g) and 12 liters of He (g), both measured at 25 °C and 1.0 atrn pressure. Calculate the total pressure in the tank at 25 °C, 2.39 atm 9.39 am 11.6 atm 22.4 atm 23.4 atm When methane (CH,) 1s burned in oxygen, water vapor and carbon dioxide ure formed. If the final pressure of the gaseous products is 6 mm Hg, what is the partial pressure of water vapor? a. 1mm Hg 2mm Hg 3 mm Hg 4mm Hg 6mm Hg The correct formula for stannous iodide is a. SblI, Srl, Snh Sbl, Snly The correct name for MgCl is a. manganese(II) chloride b. magnesium dichloride c. magnesium(IJ) chloride d. magnesium chloride e. manganous chloride Real gases do not always obey the ideal gas law because real gas molecules ‘a are attracted to one another are in constant motion are widely separated have elastic collisions have negligible intermolecular interactions Beta (B) rays are positively charged particles are electrons are high-energy rays with no charge are equivalent to microwaves are deflected by a positively charged plate For the reaction COjg) ~ 3Hag) > CHa) + H2O,e) carried out at constant pressure and temperature in a container sealed with a piston. which of the following would remain constant? a. mass of the sample b. volume of the sample €) total number of molecules in the sample density of the sample none of the above Ions and atoms that are isoelectronic have the same a. chemical properties electron affinity first ionization energy electron configuration atomic number The ionization energy with the lowest value is a. the first ionization energy of Rb the second ionization energy of Rb the first ionization energy of Ca the second ionization energy of Ca the third ionization energy of Ca The effective nuclear charge is the arrangement of electrons around the nucleus of an atom or ion measure of an atom’s tendency to gain an electron charge actually felt by the electrons amount of energy needed to remove the most loosely bound electron from a mole of gaseous atoms With respect to the size of the species, which of the following relationships is correct? a. K<K™ c)< cr se <cr Cr* <cr* O>N Which of the following molecules do not follow the octet rule? Q)HS (2) BC) (3) PH; (4) SE, aL, ¢ What is the coefficient of H1O when the following equation is properly balanced with smallest set of whole numbers? ALC; + HO +> __ AKOH); + CH; eBeO sp ¢ Which of the following is a nonelectrolyte a. NaOH b. HNO; *. CH3COOH (acetic acid) d. KF é. C2H¢0 (ethanol) * According to the solubility rules, which one of the following is soluble in water? a. HgCl, .Na2S ¢ . AgCO; Ag S . BaSQ, own ¢ The oxidation number of Clin ClOs is a.-] ~ b. +1 2 c. +3 d. +S er? ¢ Which of the following equations does not represent an oxidation-reduction reaction? a3 Al + 6HC] > 3H) - AICh b.2 H20 > 2 Hp _ O2 c.2NaCi + Pb(NO3)2 > PbCl. + 2 NaNO; d.2Nal+Bro > 2NaBr + L e. None of these ¢ How many grams of Cl; can be prepared from the reaction of 15.0 g of MnO: and 30.0 g of HCl according to the following equation? MnO, + 4HCl - MnCl, + Cl; + 2H20 ¢ What is the theoretical yield of vanadium that can be produced by the reaction of 40.0 g of V20s with 40.0 g of calcium according to the following equation? V20s (s) + 5Ca(l) > 2Vd) + 5 CaO ({s) i) OQ ~) to to wg SPW 7a G2 gq a gp ui lon e One mole of iron a. is heavier than one mole of lead (Pb) b. is 77.0 g of iron c. is 26.0 g of iron d. weighs the same as one mole of lead e, none of these ¢ Which of the following contains the greatest number of atoms? a. 100 g of Pb b. 2.0 moie of Ar c. 0.1 mole of Fe d. S g of He e, 20 million O2 molecules e How many atoms are in 6.0 g of NasN? a. 3.6 x 107 atoms b. 4.6 x 10°? atoms ¢. 1.3 x 107 atoms d. 0.217 atoms e. 0.072 atoms e Which element has the following electron configuration? [Kr]5s4d!°5p° a.Sn b c. Pb d. Bi e. Te An atom ofiron has __ unpaired electrons and is a. 0, diamagnetic . 6, diamagnetic . 3, paramagnetic _ 5, paramagnetic . 4, paramagnetic ¢ A molecule of the type ABsE2 has the geometry: a. tetrahedral b. distorted tetrahedron c. octahedral d. square planar e@. square pyramidal e The geometry of the CIF3 molecule is best described as: a. distorted tetrahedron b. trigonal planar c. tetrahedral d. T-shaped e. trigonal pyramidal According to the VSEPR theory, the geometry of the atoms in the carbonate ion. CO37 is a. square planar b. tetrahedral c. trigonal planar d. pyramidal e. octahedral According to the VSEPR theory, which of the following species is linear? . 2S . HCN . BF . H2CO . SO2 e Identify the reducing agent in the following equation. Cd + NiO2 + 2H20 — Cd(OH) - Ni(OH)2 a, Cd b. NiO» Cc. H20 d. Cd(OH); e. Ni(OID. e Which of the following is a disproportionation reaction? a. 2C2H6(g) + 702(g) > 4CO2(g) + 6H20 b.2KBr(aq) + Ch(g) > 2KCl(aq) + Br (1) c.2 H:0; (ag) > 2H2O() = O2(g) ¢ Complete this sentence: Atoms emit visible and ultraviolet light as electrons jump from lower energy levels to higher levels. as the atoms condense from a gas to a liguid. as they are heated and the solid melts to form a liquid. a. b. c. as electrons jump from higher energy levels to lower levels. d. e. as the electrons move about the atom within an orbit. * Calculate the wavelength associated with a 2°Nie* jon moving at a velocity of 2.0 x 10° m/s. The atomic mass of Ne-20 is 19.992 amu. a.1.0x 10" m b.1.0x 107° m c. 1.0 x 107% m d. 9.7 x 107° m e. 2.0x 10% em e A possible set of quantum numbers for the last electron added to complete an atom of gallium Ga in its ground state is n ] m, Ms 0 -1/2 0 -1/2 0 +1/2 ] +1/2 1 +1/2 Bw Bu