NOTE 1: You MUST SHOW ALL WORK where applicable and always use sig figs! NOTE 2: There are equations and conversions at the end of the Exam! NOTE 3: For all atomic masses, you MUST use the SUPPLIED...

20 chem questions linked below


NOTE 1: You MUST SHOW ALL WORK where applicable and always use sig figs! NOTE 2: There are equations and conversions at the end of the Exam! NOTE 3: For all atomic masses, you MUST use the SUPPLIED Periodic Table (last page of the Exam)! 1) (4 pts) Balance the following equation, and say why it is or is not a redox reaction: K (s) + N2 (g) → K3N (s) 2) (5 pts) Write and balance the equation for the decomposition of potassium chlorate to potassium chloride and oxygen gas. 3) (4 pts) How many carbon atoms are in 400. molecules of C4H4S2? 4) (5 pts) In the following balanced Redox reaction, state which species is the oxidizing agent, and which is the reducing agent: Explain your choices! 2 Al (s) + 3 CuCl2 (aq) → 2 AlCl3 (aq) + 3 Cu (s) 5) (6 pts) Determine the oxidation number of the bold underlined atoms in each species below: a) MnO3 b) ClO2– c) Co2O3 d) BaO2 e) FeBr2 f) CO32– 6) (6 pts) In which species below does chlorine have the highest oxidation number? What is that value? A) Cl2 B) ClO4 – C) PCl3 D) ClO3–E) ClO2 7) (5 pts) What is the PRODUCT for the PARTIAL oxidation of methanol? Draw its Lewis structure:CH3OH (l) + [O] ?? + H2O (l) 8) (4 pts) In the reaction shown, say whether it is an exothermic or endothermic reaction, and briefly say why: N2 (g) + 3/2 H2 (g) NH3 (g) + 11.1 kcal 9) (4 pts) Calculate the Atomic Mass of Li2CrO4. Use atomic masses to 3 decimal places, AND express your answer with the correct units. 10) (4 pts) There are __________ carbon atoms in 1 molecule of CH3CH2CO2H. 11) (5 pts) A 75.2 gram sample of sucrose (C12H22O11) contains a total of _____atoms. MM sucrose = 342.3 g/mol 12) (5 pts) What is the mass in grams of hydrogen in two molecules of (NH4)2HPO4? 13) (5 pts) How many grams of sodium phosphate are in 3.56 mol of sodium phosphate? 14) (4 pts) How many moles of Cs2CrO4 are in 842 mg of it? MM = 381.8 g mol– . 15) (4 pts) For the general unbalanced equation for photosynthesis converting carbon dioxide to glucose: CO2 (g) + H2O (l) C6H12O6 (s) + O2 (g) How many moles of glucose can be made from the complete reaction of 544 g of CO2? 16) (5 pts) Given the unbalanced chemical equation: C2H6 (g) + Br2 (l) → C2H4Br2 (l) + HBr (aq) What mass of HBr is produced if 0.884 mol of C2H6 is reacted completely? MM HBr = 80.912 g/mol 17) (6 pts) Nitroglycerin (C3H5(ONO2)3), a drug used to treat Angina in cardiac patients, is made by reacting nitric acid (HNO3) with glycerol (C3H5(OH)3): C3H5(OH)3 (l) + 3 HNO3 (aq) C3H5(ONO2)3 (l) + 3 H2O (l) MM C3H5(OH)3 = 92.0938 g/molMM HNO3 = 63.013 g/mol MM C3H5(ONO2)3 = 227.0865 g/mol If a chemist reacts 87.4 g HNO3 with 95.2 g of C3H5(OH)3, how may grams of nitroglycerin can be produced? NOTE: This is a Limiting Reactant problem! 18) (4 pts) A balloon (that can be expanded) has hot air in it. If it starts at 2.25 L at a pressure of 748 torr, what will be its pressure if 1.65 L MORE of hot air is added to it? 19) (5 pts) 2.50 L of He gas initially at -196 oC is heated to 102 oC. Given that the pressure stays constant, what will be the volume of gas (L) at the higher temperature? 20) (5 pts) What is the final temperature (oC) of a gas if 15.0 L is originally at 25.0 oC and 745 torr, and the volume is changed to 10.0 L and the pressure increased to 1.00 atm? 21) (5 pts) Assuming the can doesn’t explode (i.e., constant V), what will be the pressure (in atm) of a propellant gas, initially at 22.8 oC and 1755 torr, if it is heated to 385 oC? Equations and Information Avogadro’s number = 6.022 x 1023 “entities”/mole of that entity 1 g = 6.022 x 1023 amu760 torr = 1 atm P1V1 = P2V2 V1/T1 = V2/T2P1V1 / T1 = P2V2 / T