Name: Name: Name: Name: Worksheet 23 Chem 101 Review 1.) What is the best answer to report for? 2.) Ethylene glycol freezes at 11.5 o C. What is this temperature in o F? 3.) Three people measure a length of wood, each measures it three times. Person A gets the following measurements: 31.3 in, 31.4 in, 31.6 in. Person B reports the following: 32.2 in, 32.8 in, 32.7 in. Person C reports 32.1 in, 32.3 in, 31.9 in. The true value is 32.0 in. Comment on the accuracy and precision of each person. Back up your comments with calculations. Page 1 of 15
4.) An evacuated sphere has a mass of 198.228 g. When that same gas is filled with a certain gas it has a mass of 198.546 g. The sphere has a diameter of 9.377 cm. What is the density of the gas, to the correct number of significant figures? 5.) How many protons, neutrons, and electrons are in each of the following? 35 Cl, 41 K, 108 Ag, 65 Cu. 6.) Antimony has two stable isotopes, 121 Sb (57.21%, 120.904 amu) and 123 Sb (42.79%, 122.904 amu). Calculate the average atomic mass of antimony. 7.) Nitrogen has two stable isotopes: 14 N ( 14.003074002 amu) and 15 N (15.000108898 amu). Calculate the percent abundance of these two isotopes. Page 2 of 15
8.) How many moles or arsenic are there in 6.509 g of As? 9.) How many atoms are there in 30.127 g of magnesium? 10.) What mass of mercury contains the same number of atoms as 97.222 g of helium? 11.) Calculate the kinetic energy of a 7.45 gram projectile traveling at 1,023 feet per second. (5,280 feet = 1.609 km). 12.) Calculate the wavelength (in nm) of light which ahs a frequency of 3.14 x 10 14 s 1. 13.) Calculate the energy per photon of light that as a wavelength of 624 nm. 14.) Calculate the maximum kinetic energy of an electron ejected by a photon of light that has a wavelength of 650. nm when that photon strikes a piece of metal that has a binding energy of 2.499 x 10 19 J. Page 3 of 15
15.) Calculate the energy of an electron in the n = 3 state in a hydrogen atom. 16.) Calculate the E of an electron in a hydrogen atom that goes from n = 1 to n = 4. 17.) What wavelength (in nm) of light is emitted when an electron in a hydrogen atom drops from n = 4 to n = 2? 18.) Calculate the de Broglie wavelength of a deterium atom (2.014 amu) moving at 2.998 x 10 8 m/s. 19.) Calculate the minimum uncertainty in position of an electron in a hydrogen atom that is traveling at 5 x 10 6 m/s. Take the mass of an electron as 9.11 x 10 28 g. 20.) How many orbitals are in a subshell with n = 3 and n = 2? Page 4 of 15
21.) How many subshells are there in a n = 3 shell? 22.) How many total orbitals are there in an n = 4 shell? 23.) How many orbitals are in a 5f subshell? 24.) Write the electron configuration for Ti. 25.) Which element is represented by the electron configuration 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 3? 26.) Arrange the elements Ca, Sr, and Ba in order of increasing first ionization energy. 27.) Which of the following elements has the greatest first electron affinity, Se, Cl, or Br? 28.) Write the ground state electron configuration for Ti 2+. 29.) Identify each of the following as diamagnetic or paramagnetic. Co 2+, Co 3+, Ni 2+, Cu +, Cu 2+, Zn 2+ 30.) Arrange the following in order of increasing radius: K +, Ar, Ca 2+, Cl. 31.) Arrange the following in order of increasing lattice energy: KF, LiF, KCl, KI. 32.) What is the correct name for PbS? 33.) What is the correct formula for iron(iii) nitride? Page 5 of 15
34.) What is the correct formula for carbon tetrabromide? 35.) What is the correct name for P 2 I 4? 36.) What is the correct formula for nickel(ii) nitrate hexahydrate? 37.) What is the correct name for HNO 2? 38.) What is the formula mass of iron(iii) chromate? 39.) What is the percent composition by mass of sodium bicarbonate? 40.) How many moles of hydrogen are in 7.29 g of NH 3? Page 6 of 15
41.) Determine the empirical formula and molecular formula of a compound that has the following mass percent composition: 48.6% C, 8.2% H, 43.2% O. It s molecular mass is 148 g/mol. 42.) Which of the following has the most polar bonds? H 2 O, BCl 3, or PCl 5. 43.) Draw the correct Lewis structures for HCO 2 H and H 2 O 2. Page 7 of 15
44.) Draw the best Lewis structure for NCO. Determine the formal charge on each atom in this compound. 45.) Draw all resonance forms for SO 2. Page 8 of 15
46.) Draw Lewis structures for the following compounds. BrO 3, BBr 3, ICl 2. 47.) Draw Lewis structures for the following molecules, give their molecular geometry, and give all bond angles. CO 3 2 and ClO 3. Page 9 of 15
48.) Determine which of the following molecules are polar. HBr, CH 4, CS 2, SO 2, NH 3, XeF 2. 49.) According to valence bond theory, how many bonds is a nitrogen atom in it s ground state expected to form? 50.) Determine the hybridization of the central atom in the following compounds. SF 6, XeF 2, CO 2, BF 3, NH 3. Page 10 of 15
51.) Determine the bond order of C 2 2+ and determine whether it is diamagnetic or paramagnetic. 52.) Balance the following equations. CH 4 (g) + H 2 O(g) H 2 (g) + CO 2 (g) S(s) + O 3 (g) SO 2 (g) 53.) What is the empirical formula of a compound containing C, H, and O if the combustion of 1.23 g of the compound produces 0.74 g H 2 O and 1.8 g CO 2? Page 11 of 15
54.) How many grams of iron(iii) oxide must react with excess carbon monoxide to produce 123.4 g of iron according to the following equation? Fe 2 O 3 (s) + 3CO(g) 2Fe( s) + 3CO 2 (g) 55.) What is the percent yield when 10.49 g of CH 3 OH react with excess O 2 to give 9.23 g CO 2 according to the following equation? 2CH 3 OH(l) + 3O 2 (g) 2CO2(g) + 4H 2 O(g) Page 12 of 15
56.) Classify each of the following compounds as a strong electrolyte, a weak electroyte, or a nonelectrolyte. LiCl, KNO 3, (CH 3 ) 2 NH, HNO 2. 57.) Write the balanced net ionic equation for the reaction between aqueous iron(ii) nitrate and sodium carbonate. 58.) Identify the Brønsted acid and the Brønsted base in the following reaction. H 2 SO 4 (aq) + 2NH 3 (aq) (NH4) 2 SO 4 (aq) 59.) Identify the oxidizing agent and the reducing agent in the following reaction. Mg(s) + 2HCl(aq) MgCl2(aq) + H 2 (g) 60.) Calculate the mass of glucose (C 6 H 12 O 6 ) required to prepare 750. ml of a 1.75 M solution of glucose. 61.) How many ml of a 0.937 M solution of HCl must be diluted to a total volume of 125 ml to prepare a 0.175 M solution of HCl? Page 13 of 15
62.) If 15.0 ml of an H 2 SO 4 solution requires 28.82 ml of a 0.322 M solution of NaOH to neutralize it, what is the concentration of the H 2 SO 4 solution? 63.) Given the following thermochemical equation, calculate the amount of thermal energy released when 269 g of Br 2 (l) is consumed in this reaction. H 2 (g) + Br 2 (l) 2HBr( g) H = 72.4 kj 64.) A reaction releases 21.82 kj of thermal energy in a constant pressure experiment. The calorimeter contains 183.2 g of water and is initially at a temperature of of 20.2 o C. Assuming the calorimeter does not absorb any thermal energy, calculate the final temperature of the system. Page 14 of 15
65.) Methane, CH 4, diffuses 2.433 times as fast as a related compound. What is the molar mass of the other compound? 66.) Convert the pressure of 1748 torr to atm. 67.) The initial temperature of a gas is 21.3 o C at a pressure of 749 torr when it occupies a volume of 722 ml. What will it s temperature be when that gas occupies a volume of 539 ml at a pressure of 777 torr? 68.) Calculate the mass of neon gas that occupies a volume of 488 ml at a temperature of 17.3 o C and a pressure of 735 mmhg. Page 15 of 15