102f21_Exam1A

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City University of New York Hunter College Department of Chemistry GenChem I Fall 2021 Exam 1A 1 Name _______________________________________________________________________________________________ General Chemistry I Fall 2021 – Exam 1 Version A Instructions: 1. Do NOT open this exam until you are told to do so. Opening the exam before the start of the exam is considered an act of Academic Dishonesty. 2. All answers must be bubbled into the scantron answer sheet. 3. No credit will be given for answers written on this exam. 4. You must use a #2 pencil to bubble in the answers on your scantron. 5. This is a multiple choice exam consisting of 31 questions (8 pages). Each question is worth 6.67 points. There are a total of 206.77 points on this exam. 200 points is full credit. 6. Attached to the back of this exam you will find 2 blank pages and a periodic table. You may remove these from the exam at your convenience. 7. On the FRONT of your scantron.  Write your last name, followed by your first name.  Write your exam version (A or B) 8. On the BACK of your scantron:  Write and bubble in BOTH your last and first name. Make sure to bubble in your names as follows: Last Name (SPACE) First Name NOTE: You must Bubble in the space on your scantron! Academic Dishonesty Statement: Academic dishonesty (e.g., cheating, plagiarism, obtaining unfair advantage and falsification of records and official documents) is prohibited in The City University of New York. Penalties for academic dishonesty include academic sanctions, such as failing or otherwise reduced grades, and/or disciplinary sanctions, including suspension or expulsion. Academic dishonesty is a serious violation of the accepted values of the College. Students who are caught cheating on this exam will automatically obtain a grade of ZERO for the exam and will be reported for Academic Dishonesty.

City University of New York Hunter College Department of Chemistry GenChem I Fall 2021 Exam 1A 2 Multiple Choice Questions (6.67 pts each) 1) Which of the following name/symbol combinations is incorrect? a. Boron/B b. Silver/Si c. Copper/Cu d. Barium/Ba e. Manganese/Mn 2) The base unit for a kilowatt is the ___ and there are ___ kilowatts in one of these base units. a. kilowatt, 1 b. kilo, 10 -3 c. kilo, 10 3 d. watt, 10 -3 e. watt, 10 3 3) Determine the correct number of protons, neutrons, and electrons in the isotope shown to the right. a. p = 52, n = 24, e =52 b. p = 52, n = 52, e =24 c. p = 28, n = 24, e =24 d. p = 24, n = 28, e =28 e. p = 24, n = 28, e =24 4) Which of the following species represents a particle with 4 protons and 2 electrons? a. Be 2+ ion b. Be 2- ion c. He 2- ion d. He atom e. Ne atom 5) [Ar]4s 2 3d 10 is the short hand electron configuration for _______ . a. Ca b. Ni c. Zn d. Cd e. Kr 6) The substance As 2 O 5 is a/an ___________ compound and is correctly named as ___________. a. covalent; arsenic oxide b. covalent; diarsenic pentoxide c. covalent; pentarcenic dioxide d. ionic; arsenic oxide e. ionic; pentarsenic dioxide 𝑪𝒓 𝟐? ?𝟐

City University of New York Hunter College Department of Chemistry GenChem I Fall 2021 Exam 1A 3 7) Ca(ClO 3 ) 2 is the correct chemical formula for ___________. a. calcium chlorate b. calcium chlorite c. calcium (II) cloride d. calcium (II) clorite e. calcium dichlorate 8) There are 5,280 feet in a mile and 1.690 kilometer in a mile. Which equation below represents the number of feet in a kilometer? a. 1𝑘𝑚 ∗ 1.690𝑘𝑚 1𝑚𝑖 ∗ 5280𝑚𝑖 1𝑓𝑡 b. 1𝑘𝑚 ∗ 1.690𝑚𝑖 1𝑘𝑚 ∗ 5280𝑓𝑡 1𝑚𝑖 c. 1𝑘𝑚 ∗ 1𝑚𝑖 1.690𝑘𝑚 ∗ 5280𝑓𝑡 1𝑚𝑖 d. 1𝑘𝑚 ∗ 1𝑘𝑚 1.690𝑚𝑖 ∗ 1𝑚𝑖 5280𝑓𝑡 e. 1𝑘𝑚 ∗ 1𝑚𝑖 1.690𝑘𝑚 ∗ 1𝑓𝑡 5280𝑚𝑖 9) What is the correct formula for iron (II) sulfite? a. FeSO 2 b. FeSO 3 c. Fe 2 SO 3 d. Fe 2 SO 4 e. Fe(SO 3 ) 2 10) Which of the following species is represented by the electron configuration 1 s 2 2 s 2 2 p 6 3 s 2 3 p 6 4 s 1 3 d 5 ? I. Mn + II. Fe 2+ III. Cr a. I only b. III only c. II and III only d. I and III only e. I, II, and III 11) The oxygen atom is paramagnetic because it has _____ unpaired electrons. a. 0 b. 1 c. 2 d. 4 e. 6

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City University of New York Hunter College Department of Chemistry GenChem I Fall 2021 Exam 1A 4 12) When iron metal is exposed to fluorine gas the compound iron (III) fluoride is formed. What is the coefficient in front of the iron when the chemical reaction for this process is properly balanced? a. 0 b. 1 c. 2 d. 3 e. 6 13) Which of the following is a balanced chemical equation? a. Na 2 S + AgNO 3 → 2NaNO 3 + Ag 2 S b. 2Mg + 2HCl → MgCl 2 + H 2 c. Fe 2 O 3 + 3C → 2Fe + 3CO 2 d. SO 2 + 2H 2 O → 2H 2 SO 4 e. 2KClO 3 → 2KCl + 3O 2 14) Which one of the following molecules shows 4 bonding electrons? Hint: Think about Lewis structures for these molecules. a. H 2 O b. CH 4 c. SiO 2 d. Both SiO 2 and H 2 O e. Both SiO 2 and CH 4 15) Balance the following equation with the smallest whole number coefficients. Choose the answer that is the sum of the coefficients in the balanced equation. PtBr 4 + XeF 2 → PtF 6 + BrF + Xe a. 24 b. 16 c. 14 d. 12 e. 5 16) How many oxygen atoms are there in 13 formula units of Cr 3 (PO 4 ) 2 ? a. 104 O b. 52 O c. 28 O d. 13 O e. 8 O 17) Which of the following pairs of name and chemical formula is incorrectly matched? a. copper (I) sulfate: Cu 2 SO 4 b. oxygen dichloride: OCl 2 c. trinitrogen pentoxide: N 3 O 5 d. sodium nitride: Na 3 N e. aluminum chloride: AlCl

City University of New York Hunter College Department of Chemistry GenChem I Fall 2021 Exam 1A 5 18) Draw the correct Lewis structure for the HCP molecule. This correct Lewis structure shows _______. a. 1 C-H bond, 1 C-P bond, 2 lone pairs of electrons on the C atom, and 3 lone pairs of electrons on the P atom b. 1 C=H bond, 1 C=P bond, and two lone pairs of electrons on the P atom c. 1 C-H bond, 1 C=P bond, 1 lone pair of electrons on the C, atom and 2 lone pairs of electrons on the P atom d. 1 C- H bond, 1 C≡ P bond, and 2 lone pairs of electrons on the P atom e. 1 C- H bond, 1 C≡ P bond, and 1 lone pair of electron s on the P atom 19) Suppose scientists discover a new naturally occurring element with atomic number 159. They find two stable isotopes of this element: one with the atomic mass of 346.8 u and one with the atomic mass of 349.8 u. The natural abundances of these isotopes are 73.5% and 26.5% respectively. What is the mass number for this new element? a. 159.0 u b. 349.0 u c. 348.3 u d. 347.6 u e. 345.2 u 20) Which statement concerning the interactions between two atoms is not correct? a. As two positively charged ions get closer to each other, they repel each other. b. As two atoms get extremely close to one another, they repel each other. c. When two atoms are one bond length apart, attraction between them is stronger than repulsion between them. d. When two atoms are one bond length apart, the electrons on one atom are attracted to the nucleus of the other atom. e. If two atoms are very widely separated, there is very little attraction between them. 21) When a diatomic molecule dissociates to form two atoms, the potential energy of the system goes ______ and the temperature of the surroundings goes ________. a. up, up b. down, down c. down, up d. up, down e. Depends on the type of bond. 22) Which statement correctly describes an exothermic chemical reaction? a. The Δ H rxn > 0, and heat is absorbed during this reaction. b. The Δ H rxn > 0, and heat is released during this reaction. c. The Δ H rxn < 0, and heat is released during this reaction. d. The Δ H rxn < 0, and heat is absorbed during this reaction.

City University of New York Hunter College Department of Chemistry GenChem I Fall 2021 Exam 1A 6 23) Consider the two diagrams shown to the right. A combustion reaction can be represented by diagram __________ because in such a reaction the energy of the system ____________. a. I, increases b. I, decreases c. II, increases d. II, decreases e. II, does not change 24) The C---O bond in CO 2 is ____________ the C---O bond in H 2 CO. Hint: Draw Lewis structures for these molecules. a. shorter and stronger than b. shorter and weaker than c. longer and weaker than d. longer and stronger than e. similar in length and strength to 25) Which of the following structures is/are not correct Lewis structure(s)? . a. I only b. II only c. III only d. I and III e. II and III 26) How many hundred molecules of phosphorus trichloride can you make if you mix 150 hundred molecules of chlorine and 150 hundred atoms of phosphorus? a. 300 hundred molecules b. 150 hundred molecules c. 100 hundred molecules d. 75 hundred molecules e. 50 hundred molecules 27) Range the following bonds from most polar to least polar: F-F, F-P, and F-S. a. F-P > F-S > F-F b. F-F > F-S > F-P c. F-S > F-P > F-F d. F-F > F-P > F-S e. F-P > F-F > F-S

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City University of New York Hunter College Department of Chemistry GenChem I Fall 2021 Exam 1A 7 28) Which of the following elements have chemical properties similar to that of sulfur, S? a. O, F b. O, Se c. P, Cl d. Cl, O e. N, Br 29) Choose the scheme shown below which most accurately describes the bonding in hydrogen bromide. a. b. c. d. e. 30) Hydrogenation of double and triple bonds is an important industrial process. The hydrogenation of ethyne to ethane proceeds according to the following equation: C 2 H 2 ( g ) + 2H 2 ( g ) → C 2 H 6 ( g ) Use the table shown to the right to calculate the standard enthalpy change for this reaction (Δ H rxn ). a. -283 kJ/mol b. 436 kJ/mol c. -768 kJ/mol d. 5337 kJ/mol e. 507 kJ/mol Question #31 is in the next page. Bond Bond Enthalpy, kJ/mol C-C 350 C=C 611 C ≡ C 835 C-H 410 H-H 436

City University of New York Hunter College Department of Chemistry GenChem I Fall 2021 Exam 1A 8 31) The latest Space X mission took 4 civilian astronauts to a circular orbit around the Earth. The orbital speed for the spacecraft was 4.75 mi/s at 590 km above the earth surface. Use the information provided and the graph shown below to estimate how many hours it took for the craft to circle the Earth once at this speed. a. 43,700 hours b. 5,500 hours c. 91 hours d. 2.6 hours e. 1.5 hours

City University of New York Hunter College Department of Chemistry GenChem I Fall 2021 Exam 1A 9

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City University of New York Hunter College Department of Chemistry GenChem I Fall 2021 Exam 1A 10 General Chemistry I: Exam Appendix Constants Equations R = 8.314 J/mol-K R = 0.082 L-atm/mol-K h = 6.626 x 10 -34 J-s c = 3.00 x 10 8 m/s N A = 6.022 x 10 23 particles/mole E = (-2.18x10 -18 J) Z 2 /n 2 E = hc/λ E = mc 2 KE = (1/2)mV o 2 KE = (3/2)nRT PV = nRT T(K) = T( o C) + 273 Solubility Rules  all ammonium salts and group 1A salts are soluble  all nitrates are soluble  most chlorides, bromides, and iodides are soluble except silver, mercury, and lead  most sulfates are soluble except calcium (slightly soluble), barium, strontium, and lead  all chlorates and perchlorates are soluble  all acetates (C 2 H 3 O 2 - ) are soluble  phosphates and carbonates are insoluble (except for ammonium and Group 1A)  chromates (CrO 4 2- ) are insoluble (except for ammonium, Group 1A, magnesium)  hydroxides are insoluble (except for ammonium, Group 1A, barium, strontium, calcium)  sulfides are insoluble (except for ammonium, Group 1A, magnesium, barium, strontium, calcium) Electromagnetic Spectrum Molecular Orbital Arrangements Wavelength (nm) 10 -3 10 -1 10 10 3 10 5 10 7 10 9 10 11 10 13 Gamma rays X rays Ultra Violet Microwaves Radiowaves Infrared VISIBLE O 2 F 2 B 2 C 2 N 2 σ 2p * π 2p * σ 2p π 2p σ 2s * σ 2s σ 2p * π 2p * π 2p σ 2p σ 2s * σ 2s Energy