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Download CHEM 120 (Basic Chemistry) Exam 1 – Form 1 | Verified Questions & Answers – LSU and more Exams Chemistry in PDF only on Docsity!
Exam 1 - Form1 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) How many of the following numbers contain 3 significant figures? 0.509 1.050 0.0500 1.06 x 1024 A) one : B) two 0.509 3 sig fig C) three 1.050 4 sig fig D) four 0.0500 3 sig fi E) none of the above , signa 1.06 x 1024 3 sig fig 2) How many significant figures are there in the answer for the following problem? [(154.7-132)*3.07] =? 0.700 ’ [(154. 7 — 132) « 3.07] A) one 0.700 B) two C) three 154.7-132 = 22.7 but 2 sig fig D) four E) none of the above 3) Which of the following represent isotopes? A: $6x B: 38x c: Hx D: 38x A) A and B Aand C have the same atomic number = 21 so they are B) A and C isotopes C)AandD D)C andD E) none of the above 4) What is the volume (in cm3) of a 9.37 g piece of metal with a density of 4.66 g/cm3? A) 425 3 lem B) 6.65 9.37 g * ——— = 2.01 cm? C) 2.01 4.66 g D) 19.5 E) none of the above Exam 1 - Form1 5) How many liters of wine can be held in a wine barrel whose capacity is 30.0 gal? 1 gal = 3.7854 L A) 1.26 10-4 B) 7.93 x 103 C) 0.126 D) 7.93 E) 114 30.0 gal * — 3.785 1ga 41 i =114L 6) The recommended adult dose of Elixophyllin®, a drug used to treat asthma, is 6.00 mg/kg of body mass. Calculate the dose in milligrams for a 112-lb person. 1 Ib = 453.59 g A) 305 B) 1,482 C)15 D) 24 E) 3.0 105 453.599 1k, 112 Ib « o cs 6.00 mg * " 1lb 10009 1lkg = 305 mg 7) What is the empirical formula for CgH4g04? A) CHO B) CH20 C) CHO2 D) C2H50 E) C2H40 CgH1604 8:16:4 2:41 8) Write the formula for calcium nitride. A) Ca3N2 B) Ca(NO2)2 C) Ca(NO3)2 D) Ca2N3 E) CaN Ca* N* Ca?* N* Ca?" sN*2 CazN2 13) What is the identity of element Q if the ion Q2+ contains 36 electrons? A) Kr B) Ge C) Se D) Sr E) none of the above #Protons = #electrons + 2 P=38 Element is Strontium (Sr) Exam 1 - Form1 14) Which combination of protons, neutrons, and electrons Is correct for the isotope of rhodium, 192Rh7 A) 64 pt, 64 n°, 45 e- B) 64 pt, 45 n°, 64 e- C) 45 pt, 64°, 45 e- D) 109 pt, 45 n°, 109 e- E) 45 pt, 109 n°, 45 e- Atomic Number = 45 Protons = 45; Electrons = 45 Neutrons = Mass Number - Protons =109 - 45 = 64 15) Osmium has a density of 22.6 g/mL. What volume (in mL) would be occupied by a 21.8 g sample of osmium? A) 2.03 x 10-3 B) 493 C) 1.04 D) 0.965 E) 2.03 x 103 1mL Os => = 0.9 L 22.6 9 Os 0.965 mL Os 21.8 g Os * 16) Iron has a density of 7.9 g/cm3- What is the mass of a cube of iron with the length of one side equal to 55.0 mm? A) 2.3 x 10-2 g B) 2.1 x 104g C)1.3* 103g D)1.4g E)4.3 x 102g Volume of cube =Lxw*h= (5.50 cm)’ = 166.375 cm? 7.99 tom3 166.375 cm3 * =13x10%g Exam 1 - Form1 17) The element X has three naturally occurring isotopes. The masses (amu) and % abundances of the isotopes are given in the table below. The average atomic mass of the element is amu. Isotope | Abundance | Mass arty 74.22 _|220.9 ay 12.78 _|220.0 218 13.00 |218.1 A) 219.7 B) 218.5 C) 220.4 D) 221.0 E) 220.42 221y + 220y + 218y (.7422*220.9) + (.1278 *220.0) + (.1300*218.1) 220.4 18) The charge on the iron in the compound Fe(Oh)3 is A) 1- B) 1+ Fe(OH)3 C) 2- Fe ** (OH)s"- D) 3+ E) 2+ X= +3 19) The correct name for H2S03 is A) sulfurous acid B) hydrosulfuric acid C) hydrosulfous acid D) sulfuric acid E) hydrogen sulfurous acid 20) The correct name for N30¢ is Acid naming rules Anion = (SO;)* use -ous ending Sulfurous acid A) nitrogen hexoxide B) trinitrogen hexaoxide C) nitrous oxide D) nitrogen oxide Molecular compound — naming rules Must use prefixes E) nitric oxide Diff: 2 LO: 2.6 14) C ID: chem13b 2.1-24+ Diff: 2 LOs 23 15)D ID: chem13b 1.1-31+ Diff: 2 LO: 1.4, 1.6 16)C ID: chem13b 1.1-32+ Diff: 3 LO: 1.4, 1.6 17)C ID: chem13b 2.1-41+ Diff: 3 LO: 24 18)D ID: chem13b 2.2-25+ Diff: 2 L@: Zz: 19)A ID: chem13b 2.2-47+ Diff: 2 LO: 2.8 20)B ID: chem13b 2.2-45+ Diff: 2 LO: 2.8 Exam 1 - Form1 
