Dr. Rick Fletcher. Clearly print your name in the name section of the Scantron answer sheet.

Transcription

1 Dr. Rick Fletcher Homework 2 Chemistry 101 March 6, 2009 There is one most correct response to each of the multiple choice questions. Choose the best answer. Each of the twenty-five questions is worth 1 point. Please work through the entire exam and circle the best answer on this exam paper. Bring this completed exam into class on Friday and transfer the responses to the Scantron sheet all at one time. We will do this at the beginning of class period on Friday, March 6. Keep this completed exam and use it to check your answers on the key that will be posted online after class on Friday. Clearly print your name in the name section of the Scantron answer sheet. Clearly place your student ID number in the SUBJECT section of the Scantron sheet cm = 1 in 454 g = 1 lb 946 ml = 1 qt 5280 ft = 1 mile 16 oz = 1 lb 4 qt = 1 gal heat = (sp. Ht.) X (mass) X (ΔTemp) T (K) = T ( C) T( F) = (1.8 X T( C)) cal = J 1 cm 3 = 1 ml Version 1 Page 1

2 1. Aqueous solutions of potassium acetate and zinc sulfate are poured together and allowed to react. What is the identity of the precipitate, if one is produced? A) K(SO 4 ) 2 B) ZnSO 4 C) K 2 SO 4 D) None of the above 2. What is the general name assigned to the elements in Group IA? A) noble metals B) alkaline earth metals. C) alkali metals D) nonmetals 3. Determine the charge on the perchlorate ion in the compound Al(ClO 4 ) 3. A) +5 B) 4 C) +3 D) 1 4. Which one of the following common laboratory compounds is named incorrectly? A) hydrochloric acid, HCl B) silver nitrate, Ag(NO 3 ) 3 C) copper(i) sulfide, Cu 2 S D) barium phosphate, Ba 3 (PO 4 ) 2 5. You have already determined that there are 3.33x10-6 moles in 2.92x10-4 grams of strontium. How many atoms of strontium are in this sample? A) 5.68x10-21 atoms B) 2.01x10 18 atoms C) 4.98x10-19 atoms D) 1.76x10 20 atoms 6. Which one of the following represents a decomposition reaction? A) 2KClO 3 (s) 2KCl(s) + 3O 2 (g) B) Cr(s) + O2(g) Cr2O3(s) C) C 2 H 4 (g) + H 2 (g) C 2 H 6 (g) D) Fe(NO 3 ) 2 (aq) + Na 2 S(aq) FeS(s) + 2NaNO 3 (aq) Version 1 Page 2

3 7. A sample of N 2 O 5 is known to contain 4.3x10 24 atoms of nitrogen. How many oxygen atoms are in this sample? A) 1.7x10 24 atoms B) 4.3x10 24 atoms C) 7.1 atoms D) 1.1x10 25 atoms 8. The charge on Group IA ions is A) 1 B) +1 C) +2 D) 2 9. What is the molecular weight for iron(iii) oxide? A) g/mole B) g/mole C) g/mole D) g/mole 10. Given the following reaction, identify the spectator ions. Pb(ClO 4 ) 2 + 2NaBr PbBr 2 + 2NaClO 4 A) Pb and ClO 4 1- B) Na + and ClO 4 1- C) not enough information D) Pb 2+ and Br A bottle in lab is filled with a liquid and is labeled as Na 2 CO 3 (aq). Based on this information, what is present in solution? A) Na 2 1+, CO 3 2-, water B) Na, CO 3, H 2 O C) Na 1+, CO 3 2-, water D) Na, C, and O 12. Of the halogens, which one is a solid at standard temperature? A) iodine B) bromine C) fluorine D) chlorine Version 1 Page 3

4 13. Which one of the following is the chemical name for NiCO 3? A) nickel(ii) carbonate B) nickel carbonate C) nickel(ii) carbon trioxide D) nickel(ii) carbonite 14. A sample of N 2 O 3 contains 0.25 moles of oxygen. How many molecules of the compound are present? A) 4.5x10 23 molecules B) 3.0x10 23 molecules C) 1.5x10 23 molecules D) 5.0x10 22 molecules 15. How many elements are in the 6 th period of the periodic table? A) 18 B) 26 C) 2 D) In the balanced chemical equation, Mg 3 N 2 + H 2 O Mg(OH) 2 + NH 3, what is the coefficient in front of the water? A) 6 B) 1 C) 2 D) Vinyl ether (C 4 H 6 O) undergoes combustion with oxygen to form carbon dioxide and water. What is the coefficient in front of the oxygen in the balanced equation? A) 3 B) 7 C) 10 D) Aqueous solutions of iron(ii) chloride and sodium hydroxide are poured together and allowed to react. What is the identity of the precipitate, if one is produced? A) NaCl B) FeOH C) Iron(II) hydroxide D) none of the above Version 1 Page 4

5 19. Which one of the following single replacement equations will result in no reaction? A) Cr(s) + Fe(NO 3 ) 2 (aq) B) Zn(s) + Pb(NO 3 ) 2 (aq) C) K(s) + Cr(NO 3 ) 3 (aq) D) Fe(s) + Zn(NO 3 ) 2 (aq) 20. What is the molecular weight for capsaicin (C 18 H 27 NO 3 ), which is responsible for the heat of a chili pepper? A) 49 g/mole B) g/mole C) g/mole D) g/mole 21. Having one mole of carbon dioxide means that you have A) 6.022x10 23 atoms of oxygen B) 1 molecule of CO 2 C) 6.022x10 23 moles of carbon D) 1 mole of carbon atoms 22. The term noble, as it applies to the elements, means A) active. B) inert. C) regal. D) expensive. 23. Which one of the following is an incorrect chemical formula for a lead(iv) compound? A) PbCl 4 B) PbO 2 C) Pb 3 (PO 4 ) 4 D) PbO 24. Which one of the following is not a match? A) FeS and iron(ii) sulfide B) CaCl 2 and calcium chloride C) SO 4 2- and sulfite ion D) NH 4 NO 3 and ammonium nitrate 25. If a sample of cobalt is composed of 3.23 moles, what is its mass? A) 196 g B) 1.95x10 24 g C) g D) 190 g Version 1 Page 5