Sample Exam 2-2 AF Dr. V. Williamson

Transcription

1 FORM D is EXAM II, VERSION 1 (v1) 1. DO NOT TURN THIS PAGE UNTIL DIRECTED TO DO SO. 2. These tests are machine graded; therefore, be sure to use a No. 1 or 2 pencil for marking the answer sheets. 3. Completely blacken the answer circle. If you change an answer, erase completely the previous mark. 4. You may remove you answer sheet from this booklet. If you have a pink test, test form A should be darkened (B for Blue), if it is not, notify your instructor immediately. 5. Fill in your last name, first name, and initial. Blacken the corresponding letters below. 6. Fill in your ID number. CAREFULLY, blacken the corresponding numbers below. 7. Fill in the Dept. Course No. and Section. The Dept. = CHEM, the Course No. = 101, and your section refers to your lab section. 8. READ THE TEST CAREFULLY. The time limit on this test is 50 minutes. 9. Mark your answers in this booklet as well as on the answer sheet so you can check your score with the key after the test. 10. There are 17 questions. Each of the 16 multiple-choice questions in the first section counts 6 points (96), and there is one multiple-choice 4 pts for a total of 100 points. 11. Your score will be calculated from the number of correct answers. There is no penalty for guessing. 12. Turn in your scan sheet, show your ID, and have your calculator checked by the TA listed on the overhead for your last name. 13. A key will be on the electronic class bulletin board at 11:30PM. This is accessed through the class homepage ( ). The class average will also be posted when it is confirmed. IMPORTANT INFORMATION: F = 1.8 C + 32 λ = h/mv / λ = -R [(1/n f ) (1/ni )] and R = X 10 m 2 2 E = -R H [(1/n f ) (1/ni )] and RH = 2.18 X J c = 3.00 X 10 8 m/s h = 6.63 X J s E n = -R H /n E23 = Avogadro s number

2 1. Calculate the formula weight (molar mass) of (NH 4 ) 2 S 4 O 6. A. 356 B. 242 C. 260 D. 288 E How many grams of oxygen atoms are in 65 g of C 2 H 2 O 2 A. 22 B. 36 C. 11 D. 18 E What is the mass percentage of hydrogen in aspirin, C 9 H 8 O 4? A. 8.96% B % C. 80.0% D. 38.1% E. 4.48% 4. Element G reacts with sodium to form an ionic compound with the formula Na 2 G. Element G is a member of group? A. X B. S C. R D. Y E. Z 5. A compound containing only carbon, hydrogen, and oxygen is analyzed and found to be 70.6% carbon, 5.9% hydrogen, and 23.5% oxygen. The molecular weight of the compound is 136. What is the molecular formula? A. C 8 H 4 O B. C 4 H 4 O C. C 9 H 12 O 3 D. C 8 H 8 O 2 E. C 3 H 4 O 6. Which of the following is (are) TRUE? I Å is equal to 3.56 x km II grams of NaOH represents moles of NaOH. III. The length of the bond in HI would be longer that that in HCl. IV. A single bond is longer than a double bond between the same atoms. A. I, IV B. III, IV C. II, III D. I, II E. all are true 7. The hybridization of iodine in IF 3 is A. sp B. sp 3 C. sp 2 D. sp 3 d E. sp 3 d 2 8. Which is the correct formula/name combination? A. H 2 SO 3 / sulfuric acid B. PNO 2 / potassium nitrite C. (NH 4 ) 3 PO 3 / ammonium phosphate D. CuC 2 H 3 O 2 / copper (I) acetate E. PCl 3 / phosphorus trichlorate

3 9. (4 pts) Which of the following would be most likely to be bonded with covalent bonds? A. Ca(OH) 2 B. CoClO 4 C. AuO 3 D. C 3 H 6 O 2 E. NiCO The geometry or shape of the molecule about the first carbon (the one connected to 2 oxygen) and the nitrogen respectively, in A. t-shaped and t-shaped B. square and square C. tetrahedral and tetrahedral D. square planar and tetrahedral E. triangular planar and triangular pyramid 11. The approximate F Xe F bond angle between 2 adjacent F in XeF 4 is A. 180 B. 120 C. 109 D. 90 E What is the formal charge on the I atom in the IO 3 - ion? A. -3 B. +4 C. 0 D. -l E Which is FALSE? A g of CaSO 4 *2H 2 O is 0.39 moles B. CuSO 4 *5H 2 O is copper (II) sulfate pentahydrate C. The reason that P can form a +3 ion is that there is stability with a fully filled s-sublevel. D. The bond in Br 2 is nonpolar. E. The Lewis dot diagram for the As atom contains 2 pair of dots and 1 single dot.

4 14. Which of the following is INCORRECT? A. Valence Bond theory assumes that covalent bonds are formed when atomic orbitals on different atoms overlap. B. Molecular orbital theory describes bonding orbitals (electrons between the two nuclei) and antibonding orbitals (electrons on the outside of each nuclei) C. VSEPR theory describes how the geometry of molecules are formed when valence electron pairs are arranged around the central atom with maximum separation D. Molecular orbital theory describes how molecular orbitals are formed from atomic orbitals E. Molecular orbital theory is used to explain molecular geometry by hybridization of orbitals. 15. There are σ and π bonds, respectively, in A. 11 and 2 B. 13 and 4 C. 13 and 0 D. 11 and 4 E. 13 and The molecule ZF 4 has 1 lone pair of electrons and sp 3 d hybridization. What would you predict about the polarity of the bonds and of the molecule? A. polar bonds, B. nonpolar bonds, C. polar bonds, nonpolar molecule nonpolar molecule polar molecule D. nonpolar bonds, E. polar bonds, polar molecule partially polar molecule 17. The Lewis dot drawing for the IF 4 - ion has lone pair(s) of electrons around the central atom. A. 1 B. 0 C. 3 D. 2 E. 5

5 Key question 6pts each (unless noted) 1 C 2 B 3 E (B=3pts) 4 A 5 D (B=3pts) 6 E 7 D 8 D 9 D=4pts 10 E 11 D 12 E 13 E 14 E 15 E= 4 pts (B,C = 2pts) 16 C(A,D,E, = 3pts) 17 D