Chemistry 1035 Test 1 - Prof. Patricia G. Amateis, Exams of Chemistry

Download Chemistry 1035 Test 1 - Prof. Patricia G. Amateis and more Exams Chemistry in PDF only on Docsity! Chemistry 1035 Test 1 September 18, 2006 THIS IS FORM A Name __________________________ 6.02 x 1023 entities/mol Choose the single best answer to each question. 1. Which of the following is an extensive property? 1. density 2. volume 3. temperature 4. boiling point 2. The surface temperature of one of Saturn’s moons has been measured as 93 K. Express this temperature in oF. 1. –180oF 2. –68oF 3. –292oF 4. –356oF 3. Diamond has a density of 0.13 lb/in3. What is its density expressed in kg/m3? (1 lb = 453.6 g; 1 in = 2.54 cm) 1. 3600 kg/m3 2. 2.32 kg/m3 3. 2.32 x 104 kg/m3 4. 79.3 kg/m3 4. Rubbing alcohol has a density of 0.786 g/mL. Calculate the mass of rubbing alcohol in a 2.00 quart bottle. (1 qt = 0.946 L) 1. 2410 g 2. 744 g 3. 912 g 4. 1490 g 5. Two balances are tested using a standard weight. The true mass of the standard is 1.000 g. The results of 5 individual measurements on each balance are recorded below. Balance A Balance B 0.8888 g 1.3110 g 0.9959 g 1.3109 g 1.1182 g 1.3111 g 1.0033 g 1.3110 g 0.9938 g 1.3110 g Average mass: 1.0000g 1.3110 g Which statement best describes the results? 1. A: good precision, good accuracy, B: good precision , good accuracy. 2. A: good precision, good accuracy, B: good precision , poor accuracy. 3. A: poor precision, good accuracy, B: good precision , good accuracy. 4. A: poor precision, good accuracy, B: good precision , poor accuracy. 5. A: poor precision, good accuracy, B: poor precision , poor accuracy. 6. Write the correct formula between an ion with 50 protons, 69 neutrons and 46 electrons, and the third period halogen. 1. PdCl2 2. SnCl4 3. SnN3 4. SnBr2 7. An unknown element, X, reacts with chlorine to form an ionic compound having the formula XCl3. If the ion X has 28 electrons, identify the element. 1. Mn 2. Ga 3. Ni 4. Ca 8. Which formula does not match the name? 1. Ba(ClO)2 barium hypochlorite 2. HBrO3 bromic acid 3. SCl4 sulfur (IV) chloride 4. Cr2O3 chromium (III) oxide 19. Consider the reaction 2 C2H2 (g) + 5 O2(g) → 4 CO2(g) + 2 H2O(g) 10.0 g of C2H2 react in excess oxygen and 28.7 g of CO2 are obtained. What is the percent yield of CO2? 1. 59.0% 2. 42.4% 3. 84.9% 4. 91.1% 20. A compound was found to contain 67.6% carbon, 22.5% oxygen and 9.9 % hydrogen. Its molar mass was determined to be 142 g/mol. What is the molecular formula of this compound? 1. C8H14O2 2. C5H2O5 3. C7H10O2 4. C6H6O4 21. What is the molarity of a solution made by dissolving 90.0 g HC2H3O2 (60.0 g mol) in enough water to produce 750. mL of solution? 1. 0.120 M 2. 2.00 M 3. 1.20 M 4. 1.12 M 22. How many grams of CaO are required for complete reaction with 275 mL of 0.523 M HCl? CaO(s) + 2HCl(aq) → CaCl2(aq) + H2O( ) 1. 14.7 g 2. 8.07 g 3. 6.15 g 4. 4.03 g 23. You have 3.75 g of each of the following elements: C, Ca, Cu, Cs, Cr. Which sample contains the largest number of atoms? 1. C 2. Ca 3. Cu 4. Cs 5. Cr 24. Calculate the number of oxygen atoms in 13.68 g of antifreeze, C2H6O2. (62.1 g/mol) 1. 8.235 x 1024 atoms 2. 1.647 x 1025 atoms 3. 2.652 x 1023 atoms 4. 1.326 x 1023 atoms 25. Three different samples containing only two elements X and Y are analyzed. Sample #1 weighs 75.00 g and contains 22.3 g of Y. Sample #2 contains 25.2% of Y. Sample #3 contains 37.99 g of X and 12.8 g of Y. Which of the following statements is correct? 1. All three samples are identical compounds 2. Each of the three samples is a different compound 3. Samples 1 and 2 are identical but sample #3 is a different compound 4. Samples 1 and 3 are identical but #2 is a different compound 5. Samples 2 and 3 are identical but #1 is a different compound Answers: 1. 2 8. 3 15. 4 22. 4 2. 3 9. 1 16. 1 23. 1 3. 1 10. 1 17. 2 24. 3 4. 4 11. 2 18. 4 25. 5 5. 4 12. 4 19. 3 6. 2 13. 2 20. 1 7. 2 14. 1 21. 2