Only report a unit-less answer on the line that corresponds to your part. Then pass the sheet to the next group.

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1 Relay Round Practice Question Answer Sheet A. 10 B. 17 C. 3 Relay Round Question #1 Answer Sheet A. 1/2 or 0.5 B. 100 C. 4:13 PM

2 Relay Round Question #2 Answer Sheet A. 22 B. 3 C. 4.2 Relay Round Question #3 Answer Sheet A. 20 B C. 2.11

3 Relay Round Question #4 Answer Sheet A B C Relay Round Question #5 Answer Sheet A B C

4 Relay Round Question #6 Answer Sheet A. 4 B C Relay Round Reserve Question 1 Answer Sheet A. C 20 H 32 O 16 B C

5 Relay Round Practice/ Warm-Up Question: Part A: Say John has 10 apples. He blends the apples into applesauce and puts the applesauce in a bowl. Consider the following information regarding the turbulent flow of the applesauce into the bowl. Calculate the pressure vector gradient of the applesauce flowing into the bowl using at least four differential equations, and then multiply that by 0 and add how many apples John had initially. Relay Round Practice/ Warm-Up Question: Part B: A wise man once said that They don t want you to win, so we gon win more. Assume that this philosopher had previously won times that day. After this statement, he wins 7 more times. How many times did he win that day? Relay Round Practice/ Warm-Up Question: Part C: The Ron Swanson Law of Pets states that any dog less than fifty pounds is a cat, and cats are worthless. How many Chihuahuas that each weighs pounds would need to get into a Great Dane costume to not be considered a cat?

6 Relay Round Question #1 Part A: Give the order of this reaction with respect to reactant B for the reaction A + 2B C: [A] (M) [B] (M) Rate (M/s) Relay Round Question #1 Part B: A reaction has H = kj/mol and S = +5 temperature in K at which the reaction will be spontaneous? J mol K. What is the minimum Relay Round Question #1 Part C: Suppose you have a g sample of radioactive material at 2:00PM. If the sample has a half-life of 20 minutes, at what time to the nearest minute will you be left with 1.0g of the sample? Don t forget AM/PM in your answer!

7 Relay Round Question #2 Part A: Based on a rule that every carbon atom must make four bonds and every hydrogen atom must make one bond, how many hydrogen atoms must there be in a linear molecule consisting of 10 carbon atoms with only single bonds? Relay Round Question #2 Part B: Consider the element with atomic number. If its four highest energy electrons were removed, what would the principal quantum number of its next highest electron be? Relay Round Question #2 Part C: Consider a system of particles in which each particle has a 60% chance of being in the up configuration and 40% to be in the down configuration. A particle in the up configuration has energy of 1eV, while a particle in the down configuration has an energy of 2 ev. If total energy is the sum of the energies of each individual particle, what is the average total energy of this system?

8 Relay Round Question #3 Part A: A photon has a wavelength of 62 nanometers. Find the energy of this photon in electronvolts (ev), given the following information. Energy (E) is related to wavelength (λ) by the following relation: E = hc λ. h = J s; c = m s ; 1 ev = J Relay Round Question #3 Part B: If exhaled air is 5% carbon dioxide by mass, and the average person exhales 15 L of air per minute, calculate the number of moles of carbon dioxide exhaled in minutes if the density of air under those conditions is kg m 3. Relay Round Question #3 Part C: g of sodium chloride is dissolved in 10 L of water with no volume change. How many grams of copper (I) nitrate can be added to this solution before a precipitate begins to form? K sp = for the precipitate.

9 Relay Round Question #4 Part A: At 298K, the vapor pressure of benzene (C 6 H 6 ) is 85 torr. 2.5 moles of a nonvolatile solute and 312 grams of benzene are mixed. Calculate the vapor pressure at 298K in torr. Assume that the solution is ideal. Relay Round Question #4 Part B: What is the ph of a buffer solution that contains grams of formic acid (HCOOH) and 0.85 moles of potassium formate (KHCOO) in 300 ml of DI water at 25 o C? pka of formic acid at 25 o C equals Relay Round Question #4 Part C: grams of HCl are added to L of water. What is the ph of the resulting solution? Give your answer to 3 decimal places.

10 Relay Round Question #5 Part A: You retrieve a stock of sodium carbonate (Na 2 CO 3, molar mass g mol ), and weigh out g of this and place the sample in a flask. You then begin titrating HCl solution into the flask from a buret, using a ph probe to determine the equivalence point. If 20 ml of HCl were required, what is the concentration of the HCl? Relay Round Question #5 Part B: If g of an unknown monoprotic weak base are dissolved in a flask, and 40 ml of M HCl are used to titrate this base to the equivalence point. What is the molar mass of the weak base? Relay Round Question #5 Part C: Obediah adds sodium chloride to ml of deionized water at 298 K. He then adds a large excess of lead (II) chloride (Molar mass = g/mol) grams of this PbCl 2 dissolve, which is much less than usual. How many grams of sodium chloride (Molar mass = g/mol) did Obediah add to the water? K sp(pbcl2 ) = at 298 K.

11 Relay Round Question #6 Part A: Draw the Lewis structures of the following molecules: NH 3, CO 3 2, XeF 2. Consider the lone pairs of electrons on the central atoms of these molecules. How many of these central atom lone pairs are there in total? Relay Round Question #6 Part B: Consider the following balanced reaction: N 2(g) + 3H 2(g) 2NH 3(g). If 16.8 grams of nitrogen gas are combined with 5.6 grams of hydrogen gas in a L container at 25, what is the pressure in the flask if the reaction goes to completion? Assume ideal gas behavior. Relay Round Question #6 Part C: Suppose 57.4 grams of a mixture of nickel, cobalt, and unknown other compounds reacts with cyanic acid to produce 36.4 grams of [Ni(CN)4] 2- and grams of [Co(CN)4] 2-. In the original sample, what is the mass percent of cobalt?

12 Relay Round Reserve Question 1 Part A: Consider an unknown compound that consists of only carbon, hydrogen, and oxygen atoms: CxHyOz. To test the compound, a group of students combusts g of their unknown compound in oxygen and retrieve g of H2O and.490 g of CO2. If the molecular weight of the compound is 528 g/mol, what is the molecular formula of the compound? Relay Round Reserve Question 1 Part B: Consider the following reaction for the production of hydrogen gas: CH 4(g) + H 2 O (g) CO (g) + 3H 2(g) Suppose we took 2 L of methane combined with excess steam, and the reaction proceeds to completion. What is the sum of the moles of product gas produced if the reaction occurs at 20 o C and 750 Torr? R = L atm K mol. Relay Round Reserve Question 1 Part C: Suppose that 4 moles of a compound are added to 1 L of water, with no change in volume. Upon addition to water, some of the compound dissociates into 2 different molecules. Assume that the ratio of compound that dissociated to un-dissociated compound is. T f = i K f m, where T f is the change in freezing point, i is the Van t Hoff Factor (degree of dissociation), and m is the molality. If K f = 1.86 K kg for water (freezing point = 0 ), what is the new freezing point of the solution? mol

APC Spring Break Take-Home Exam Instructions

APC Spring Break Take-Home Exam Instructions Complete all exam questions on separate paper. Show all work to receive credit. Partial credit will be awarded! Staple all papers together. Do NOT include the