lOMoARcPSD 29777598 Chem 1A MT1 F22 midterm 1 Chem 1A MT1 F22 midterm 1 General Chemistry University of California Berkeley General Chemistry University of California Berkeley Studocu is not sponsored or endorsed by any college or university Studocu is not sponsored or endorsed by any college or university Downloaded by Karthik S ksrin01 gmail com Fall 2022 Midterm 1 NAME SID Proctor lOMoARcPSD 29777598 Chemistry 1A Fall 2022 Midterm Exam 1 September 15 2022 90 minutes closed book Name SID Signature Proctor Name The test consists of 3 multi part questions and 11 multiple choice questions Put your answers in the boxes provided Answers outside the boxes may not be considered in grading Write your name SID and proctor name on every page of the exam Question Page Points Score Useful Equations and Constants Question A Question B Question C 2 3 4 Multiple Choice 5 6 Total 150 30 30 35 55 aP V nb nRT PV nRT 2 n 2 V 1 2 KE 2 mv N0 6 02214 x 1023 mol 1 T K T C 273 15 R 0 0821 L atm K 1 mol 1 1 atm 760 mm Hg 760 torr 1 bar A periodic table appears on Page 7 Downloaded by Karthik S ksrin01 gmail com Page 1 of 7 lOMoARcPSD 29777598 Fall 2022 Midterm 1 NAME SID Proctor A Aspirin A structural formula for aspirin C9H8O4 is shown here a Fill in the circle next to the correct molar mass for aspirin 153 g mol 175 g mol 180 g mol 194 g mol b Fill in the circle next to the largest bond angle within the aspirin molecule 90 104 5 109 5 120 180 c What causes aspirin to be a solid at 300 K Fill in exactly one circle dispersion interactions all three of these effects hydrogen bonding none of these effects dipole dipole interactions d How many equally good resonance structures does aspirin have beyond the one shown above 0 1 2 3 4 e If a dose of aspirin contains 0 0036 mol aspirin and global aspirin production per year was 35 million kg how many doses per year would there be 30 million 104 million 980 million 23 billion 54 billion Downloaded by Karthik S ksrin01 gmail com Page 2 of 7 lOMoARcPSD 29777598 Fall 2022 Midterm 1 NAME SID Proctor H CH4 CH3CH3 B Gases Consider the following four molecules and their corresponding Lewis structures CH3OCH3 HC HC H H H H H H H O H H H H H H C C C H H H H HC C C H H O H H CH3CH2CH2OH a Fill in the circle that places these in descending order of van der Waals a constants CH4 CH3OCH3 CH3CH2CH2OH CH3CH3 CH3OCH3 CH3CH2CH2OH CH3CH3 CH4 CH3CH2CH2OH CH3CH3 CH3OCH3 CH4 CH3CH2CH2OH CH3OCH3 CH3CH3 CH4 b At 600 the total kinetic energy in 1 mol of CH4 molecules is 10 9 kJ Note that 1 kJ is 1000 Joules the SI unit for energy Assuming ideal gas behavior what is the total kinetic energy in 1 mol of CH3CH3 molecules at 600 5 8 kJ 10 9 kJ 15 5 kJ 20 4 kJ insufficient information c At which of the following conditions would the ideal gas law be most trustworthy for describing the properties of CH3OCH3 40 1 atm 20 3 atm 0 1 atm 80 0 5 atm d The van der Waals constants for CH3CH3 are a 5 49 L2 atm mol 2 and b 0 0638 L mol 1 How much pressure does a real sample of 1 mol of CH3CH3 gas exert when placed in a 10 L box at 193 K 1 58 atm 1 54 atm 1 50 atm 1 46 atm 1 42 atm e What is the strongest type of intermolecular attraction that exists between the molecules in a CH3OCH3 gas London dispersion hydrogen bond ion ion ion dipole dipole dipole Downloaded by Karthik S ksrin01 gmail com Page 3 of 7 lOMoARcPSD 29777598 Fall 2022 Midterm 1 NAME SID Proctor C Baking Soda Sodium bicarbonate commonly known as baking soda is a chemical compound with the formula NaHCO It is a salt composed of a sodium cation and a bicarbonate anion a Fill in the circle next to the correct formula for the cation within the NaHCO3 salt NaH3 Na NaH2 Na Na2 b Complete this incomplete bicarbonate anion Lewis structure and draw its other resonance structure Include all lone pairs any nonzero formal charges and any overall charge H O O C O c Fill in the circle next to the best description for the type of bonding within bicarbonate Non Polar London Covalent VSEPR Ionic d Fill in the circle next to the best description for the type of bonding between the sodium cation and bicarbonate anion Ionic VSEPR Covalent Non Polar London e A cake recipe calls for 1 teaspoon of baking soda NaHCO3 If a teaspoon of baking soda weighs 6 grams how many moles of NaHCO3 are needed in the recipe 0 07 mol 0 10 mol 0 13 mol 0 16 mol 0 19 mol f Baking soda acts as a leavening agent that is it helps baked goods rise and expand by releasing CO2 gas bubbles into the cake batter as it cooks Assuming that all 6 grams of baking soda is consumed by the reaction below that any H2O molecules produced stay in the liquid batter that all the CO2 produced ends up in bubbles and that there are no other reactions what is the total volume of the bubbles produced in the batter in an oven at 350oF 176 7oC Note that we are baking at sea level so the pressure is 1 0 atm 2 NaHCO3 Na2CO3 H2O CO2 Write your answer rounded to the nearest tenth of a liter in the box below part f final answer g The carbonate anion CO3 2 is present in the Na2CO3 salt produced by the above reaction 2 What is the bond order for each carbon oxygen bond in CO3 1 2 Downloaded by Karthik S ksrin01 gmail com Page 4 of 7 lOMoARcPSD 29777598 Fall 2022 Midterm 1 NAME SID Proctor Multiple Choice Fill in exactly one circle for each question 1 For an ideal gas which of the following changes results in an increase in the pressure assuming that any unmentioned variables T n V are held constant Cutting both the volume and number of molecules in half Doubling the temperature while cutting the number of molecules in half Doubling the temperature and the number of molecules Cutting the temperature in half Doubling the temperature and the volume 2 The largest bond angle in AsCl5 is 180o 120o 109o 90o 3 The molecular shape of PF3 is bent tetrahedral T shaped octahedral pyramidal 4 Which of the following contains the most polar bond 5 Which gas has the highest average velocity at 75 O2 CHF3 Br2 CH2Cl2 CH4 all are the same not enough information SiH4 O2 CH4 6 The van der Waals a constants are 2 28 for CH4 4 38 for SiH4 and 5 74 for GeH4 …