CHM 111 Work Problems PDF

# CHEMISTRY 111 ## Work Problems 1. Convert -200 degrees F to Celsius and Kelvin 2. Make the following conversions: - 831g to Kg - 51.2mL to CC - 215cm to Km 3. The density of uranium is 18.95g/mL. What is the volume of 75g of uranium? 4. How many significant figures are there in: -...

# CHEMISTRY 111 ## Work Problems 1. Convert -200 degrees F to Celsius and Kelvin 2. Make the following conversions: - 831g to Kg - 51.2mL to CC - 215cm to Km 3. The density of uranium is 18.95g/mL. What is the volume of 75g of uranium? 4. How many significant figures are there in: - 6543 - 73.0001 - 0.000040 - 6500 5. Round off to two significant figures: - 0.393974 - 0.087498 - 31.4 6. What is the mass number of an atom with 91 protons, 88 electrons, and 140 neutrons? 7. How many electrons, protons, and neutrons are present in Sr2+ with a mass number of 87? 8. Write the complete ground-state electronic configuration for Se. Also, write the abbreviated form of Se. 9. Give the designation of all sublevels in the 4th level. How many orbitals are in each subshell? 10. How many covalent bonds are normally formed by: - Cl - C - N 11. Which species is the oxidizing agent for the following reaction: 2PbS(s) + 3O2(g) → 2PbO(s) + 2SO2(g) 12. Balance the following oxidation reduction reaction which occurs in a basic solution. Cl2(g) → Cl(aq) + ClO(aq) 13. A 25.0mL sample of HCl solution takes 24.16mL of 0.106M NaOH for complete neutralization. What is the concentration of the HCl solution? 14. Calculate the formula mass of C7H5(NO2)3. What is the molar mass? 15. How many moles of C20H24N2O2 are there in 51.6g of that compound? 16. How many moles of S atoms are there in 3.5 x 103 moles of Al2(SO4)3? 17. What is the mass in grams of a single aspirin, C9H8O4 molecule? 18. How many molecules are in one drop (0.0500g) of water? 19. Balance: - Fe2O3 + CO → Fe + CO2 - Al3+ + S2- → Al2S3 20. If 2g of N₂ is reacted with excess of H2 in the Harber reaction, - How many grams of NH3 are produced? - If 3.00 grams of H2 is reacted with an excess amount of N2 how much NH3 are produced? N2 + 3H2 → 2NH3 21. A chemist calculated the theoretical yield in a particular reaction to be 85.2g. The mass of the product actually obtained was 71.4g. What is the percentage yield? 22. How many grams of vitamin C, C6H8O6, are there in 0.731 mole of vitamin C? 23. Determine the formal charge on each atom of ClF5. 24. Determine the shape and number of bonding and non-bonding electron pairs for PO43-. 25. Determine the electron pair shape of I3-. Is the electron pair shape the same as the molecular shape? 26. Give the oxidation number of the underlined atom: - Na3PO4 - NaCl - H2SO4 - K2Cr2O7 27. What is the molarity of C9H8O4 if you have 85.0g dissolves in 250mL of solution? 28. Describe how you would prepare 250mL of 0.1M NaOH from solid NaOH and water. 29. How many electrons are represented by the quantum numbers? - n=5, M₁=0 - n=4, l=2, Ms=1/2 30. How many grams of solute are present in 125mL of a 0.0036M solution of MgCO3? (Give your answer to the correct number of significant figures) 31. What is the molarity of a solution by dissolving 4.6g (NH4)3PO4 in enough water to give 1.65L of solution? 32. What type of thermochemical reaction is represented below: C3H8 + 5O2 → 3CO2 + 4H2O + heat 33. Write all the possible sets of quantum numbers which describe an outer shell (valence) electron for Cs. 34. What mass of Barium sulfate (BaSO4) is produced when 100mL of a 0.100M solution of barium chloride is mixed with an excess amount of Iron (III) sulfate? 3BaCl2(aq) + Fe2(SO4)3(aq) → 3BaSO4(al) + 2FeCl3(aq) 35. What is the polarity of the following compounds? - CCl4 - CH3CH2OH - CH2Cl2 - NH3 36. For the compound XeF4 answer the following questions: - What is the Lewis Structure? - What is the shape of its electron pairs? - Is the molecule's shape the same as the electron pair shape? - How many sigma bonds are there? - How many pi bonds are there? - What is orbital hybridization on Xe? 37. The pressure of a 3.00L sample of argon (Ar) gas is 725mm Hg. Assuming constant temperature and moles, calculate the new pressure when the volume increases to 9.15L. 38. A 2 liter gas cylinder contains 1.9 x 102g of N2. What pressure is exerted by the nitrogen (N2) at 22°C? 39. Given the following recation: 2Al + 6H+(ag) → 2Al3+(ag) + 3H2(g) - What volume of H2 at STP could be generated from 250.9mL of dilute HCl in which the molarity of H+ is 6.0 mol/L? 40. Name the following compounds: - CuBr - Mg3N2 - CCl4 - CS20 Write the formula for the following compounds: - Potassium fluoride - Phosphorus tribromide - Sodium nitrate - Ammonium sulfate 41. Calculate ΔH for the process Mn(s) + O2(s) → MnO2(s) from the following information: - 2Mn(s) + O2(g) → 2MnO(s) ΔH = -770.4KJ - 2MnO(s) + O2(g) → 2MnO2(s) ΔH = -269.7KJ 42. Given: - 2CO(g) + O2(g) → 2CO2(g) ΔH = -566.0KJ - C(s) + O2(g) → CO2(g) ΔH = -393.5KJ - Calculate ΔΗ for the reaction C(s) + 1/2O2(g) → CO(g) 43. How much heat is given off when 1/2 mole of liquid water cools from 100.0°C to 10.0°C? 44. When 5.00g of calcium chloride, CaCl2 is added to 100.0g of water in a coffee cup calorimeter, it dissolves: - CaCl2(s) → Ca2+(aq) + 2Cl-(aq) - And the temperature rise from 25.00°C to 28.51°C. Assuming that all heat given off by the reaction is transferred to the water calculate "q" for the reaction system. 45. In a certain experiment, 28.0mL of 0.250M HNO3 and 53.0mL of 0.320M KOH are mixed. Calculate the amount of water formed in the resulting recation. - HNO3(aq) + KOH(aq) → H2O(l) + KNO3(aq) 46. Write the net ionic equation for the following chemical equation: - NaOH(aq) + FeCl3(aq) → 3NaCl(aq) + Fe(OH)3(s) - Which ions are spectator ions?