CHM 1110 F2012 Sample Exam 3 Use the following unbalanced reaction for questions 1-3. Al4C3(s) + 10.0 g FW = 143.95 g/mol H2O(l) → Al(OH)3(s) + 10.0g 18.00 g/mol 78.00 g/mol CH4(g) 1. Write the balanced equation below. (4 points) 2. If the above masses are used, what is the limiting reagent? What is the theoretical yield of Al(OH)3? (10 points) 3. How much non-limiting reagent is left over? (8 points) Use the following information for questions 4-6. 45.0 mL of 0.524 M H2SO4 4. How many moles of H2SO4 are present in the beaker? a) 0.0236 mol b) 0.524 mol c) 23.6 mol d) 0.0116 mol 5. Write the neutralization reaction (with products) that would take place between H2SO4 and NaOH. (4 points) 6. If this beaker was spilled on the lab floor, how many mL of 0.61 M NaOH solution would it take to completely neutralize it? (8 points) 7. Which of the following statements about acids is not true? a) Acids are H+ donors. b) Acids are strong electrolytes. c) HF is a strong acid. d) Acids ionize in water to form hydronium. Use the following incomplete reaction for questions 8-12. (NH4)2CO3 (aq) + CaBr2(aq) → ??? FW = 96.10 g/mol 199.88 g/mol 8. Write the complete balanced reaction. Please include all products and phases.(3 points) 9. Write the ionic equation. Please include all products, charges, and phases. (3 points) 10. Write the net ionic equation. Please include all products, charges, and phases. (3 points) 11. Which of the following statements is correct about solutions? a) Solutions are heterogeneous mixtures. b) Solutions always have the same amount of solute. c) Solutes are present in larger amounts than the solvent. d) The solubility of a solute is the maximum amount that can be dissolved. 12. If 12.36 g of (NH4)2CO3 is dissolved in a total solution volume of 250 mL, what is the concentration? a) 49 M b) 5.1x10-4 M c) 0.049 M d) 0.51 M Use the following molecule for questions 17-21. TeF4 17. Draw the Lewis dot structure for TeF4. (6 points) 18. What is the electronic geometry of the Te? (2 points) 19. What is the molecular geometry of TeF4? (3 points) 20. What is the hybridization of the Te in TeF4? (3 points) 21. What is the hybridization of any of the F atoms in TeF4? (3 points) Use the following molecule for questions 22-25. BrF5 22. Draw the Lewis structure for BrF5. (5 points) 23. What is the electronic geometry of BrF5? (2 points) 24. What is the molecular geometry of BrF5? (3 points) 25. Draw the energy level orbital hybridization diagram for Br in BrF5. This should show which orbitals are hybridized as well as the correct number of electrons in both the atom and the molecule. (6 points)