General Questions and Answers

Be sure to answer all parts Balance the equation Remember to include states of matter CH4 g Cl g CCl4 g HCl g

True or False 1 mole of O and 1 mole of CO2 contain the same number of atoms True O False

A sample of gas occupies 60 2 mL at 31 C and 827 mmHg Find the volume of the gas in mL at STP Report your answer to 3 significant figures Do not include units

in the name and empirical formula of each ionic compound that could be formed from the ions in this table Some ionic compounds empirical formula cation K 4 Pb 2 Fe anion MnO 4 NO CIO3 11 0 name of compound 0 U X

True or False Silver nitrate AgNO3 forms a precipitate in aqueous solutions True False

Give a definition or description for the following term Electron affinity

Which one of these reactions is an acid base reaction O 2Al s 3H SO4 aq Al2 SO4 3 aq 3H g 2KBr aq Pb NO3 2 aq 2KNO3 aq PbBr s OCaBr aq H SO4 aq CaSO4 s 2HBr g O Al OH 3 aq 3HNO3 aq AI NO3 3 aq 3H O l O CO32 aq HSO4 aq HCO3 aq SO4 aq

Classify the reaction between sodium chloride and mercury I nitrate 2NaCl aq Hg2 NO3 2 aq NaNO3 aq Hg2Cl2 s acid base reaction oxidation reduction reaction O precipitation reaction O combination reaction O decomposition reaction

One of the many chemical warfare agents banned by the 1993 Chemical Weapons Convention is phosgene Many of these chemical agents are denser than air so that they replace oxygen and cause suffocation of their victims apart from the chemical damage to lungs and burning of skin eyes and mucous membranes 2 298 2 L of phosgene has a mass of 10 0 kg at 25 C and 1 atm pressure Question What is the density of phosgene at 25 C and 1 atm pressure Show calculations Use correct units

Gas Laws What is the mass in grams of 6 9 L of O at 41 7 C and 746 7 mmHg

Nitrogen and hydrogen react to form ammonia in a closed container kept at 100 C 373 K and constant volume according t the reaction N g 3H g 2NH3 g The pressure of H and N in the container before the reaction is 866 mmHg What is the pressure after all nitrogen and hydrogen have been converted to ammonia Show your calculations Use the correct number of significant figures and the correct units

How many grams of potassium bromide will be produced when 5 00 grams of metallic potassium reacts with excess Br2 g Give a balanced equation for the reaction Show your calculations Use the correct number of significant figures and the correct units

What are the standard conditions for thermochemistry and reaction energy calculations O 1 0 K 1 atm O 273 15 K 76 mmHg O 0 C 1 atm O 273 15 C 760 torr O 298 15 K 1 atm

Give a definition Molarity or description for the following term

The estimated amount of recoverable oil from a field at Prudhoe Bay in Alaska is 1 3 x 1010 barrels What is this amount of oil cubic meters One barrel 42 gal exact 1 gal 4 qt exact and 1 qt 9 46 x 10 4 m www ww Show your calculations Use correct significant figures in the answer Give your answer in the textbox below

Exercise J Identifying acidic solutions by pH Circle the most acidic pH in each group 2 5 1 5 10 2 12 0 9 1 5 1 3 18 7 4 12 7 10 5 7 5 2 4 3 2 6 8 5 3 8 11 2 7 6

The combustion of butane results in the formation of water and carbon dioxide Which is the correctly balanced equation C4H10 l O2 g H O g CO2 g O C6H 902 g 3H O g 6CO2 g O C4H10 902 g 6H2O g 6CO2 g 2C4H10 l 1502 g 6H O g 12CO2 g O 2C4H10 l 1302 g 10H O g 8CO2 g O 2C4H10 l 902 g 6H O g 12CO2 g

20 Balance the following oxidation reduction reaction using the half reaction method assume the solution is acidic 5 points Cr O72 12 Cr 103

nitions and Descriptions Give a definition or description for the following term Electronegativity

32 You titrated an 9 875 mL of an HCI solution with a 0 106 molar solution of sodium hydroxide The phenolphthalein endpoint was 13 86 mL What is the concentration of my HCI solution 3 points

How many moles of HCI can be formed when 2 0 moles of molecular hydrogen gas H react with excess molecular chlorine Cl2 according to the reaction H g Cl g HCI g unbalanced equation 0 5 mol O 1 0 mol 2 0 mol 4 0 mol 8 0 mol

Acetic acid is produced commercially by the reaction between methanol and carbon monoxide CH OH CO g HC2H3O2 1 When 250 moles methanol are mixed with 200 moles carbon monoxide the amount of acetic acid produced is 450 mole O 250 moles O200 moles 50 moles O 450 liters

The rest mass of a proton is 1 0072783620 u and that of a neutron is 1 0086687408 u The 1271 nucleus weighs 126 988252 u Calculate the mass defect of the nucleus in a Report your answer with 5 places after the decimal point Do not report unit in your answer

The electron configuration of a ground state Co atom is O Ar 4s 3d7 O 1s 2s 2p 3s 3d O Ne 3s 3d7 O Ar 4s 3d5 O Ar 4s 4d7

Which of the following substances is an acid O NH3 O CH3CH OH O SO4 O HF O NaOH

Cations and anions tend to be formed in reactions between the following types of atoms O Non metals O Metals O Non metals and group 18 elements Metals and non metals O Metals and metalloids

If a rock sample was found to contain 6 78 x 10 7 mol of argon 40 how much potassium 40 would also have to be present for the rock 1 3 x 10 years old The half life of K 40 is 1 3 x 10 years mol K 40

The combustion reaction of methane is CH4 g 202 g CO g 2H O g What is the reaction enthalpy AHrxn given the following data AH for CH4 g 74 6 kJ mol AHf for CO g 393 5 kJ mol AHf for H O g 241 8 kJ mol Show all calculations

Which element gets oxidized and which one gets reduced in the correct order in the following reaction 2Cu 41 2Cul 12 O Cu2 gets oxidized and I gets reduced O Cul gets oxidized and I gets reduced Cul gets oxidized and 12 gets reduced Olgets oxidized and Cu2 gets reduced O 12 gets oxidized and Cut gets reduced

The electron configuration 1s 2s 2p 3s 3p4 refers to O sulfur S O sulfide ion S O phosphorus P O aluminum ion Al Ochloride ion Cl

lodine is a solid nonmetal at room temperature The isotope 1251 is radioactive and often used in medicine and biochemical research as a tracer for metabolic processes Select the combination that lists the number of protons and neutrons and the mass number O 35 90 125 O 53 72 125 O53 78 131 O 53 131 184 53 72 131

A sample of oxygen occupies 15 0 L What is the effect on the volume when the pressure is doubled O The volume doubles to 30 0 L O The volume decreases to 7 50 L O The volume quadruples to 120 0 L O The volume remains 15 0 L O You need to know the exact temperature and pressure change

New industrial plants for acetic acid react liquid methanol with carbon monoxide in the presence of a catalyst CH3OH I CO g HC H3O 1 In an experiment 15 0 g of methanol and 10 0 g of carbon monoxide were placed in a reaction vessel What is the theoretical yield of acetic acid If the actual yield is 19 1 g what is the percentage yield Show your calculations Use the correct number of significant figures and the correct units

Which of the following compounds is an ionic compound ZnO OH3PO4 OCUK O N O5 O CO

What are the Standard Temperature and Pressure conditions for gas laws O 0K 1 atm O 273 15 K 76 mmHg O 0 C 1 atm O 15 C 760 torr O 15 K 1 atm

Fill in the Blank Give your answer in the available space In a redox reaction the loss of a n is called

Which of the following elements has the highest electron affinity O Magnesium Mg O Phosphorus P Aluminum Al Chlorine Cl Sulfur S

Based on the solubility rules what will happen when a solution of Pb NO3 2 aq is mixed with a solution of Kl aq See provided information in the back of the exam KNO3 will precipitate Pb2 and I are spectator ions O No precipitate will form Pb NO3 2 will precipitate K and I are spectator ions Pbl2 will precipitate K and NO3 are spectator ions Pb2 and I are spectator ions and Pbl2 will precipitate

Question 1 Pressure is measured in different units atmosphere atm mmHg torr pascal psi One atm pressure is equal to O 12 psi 560 torr O 760 mmHg 1 mmHg 2 5 P

If a rock sample was found to contain 9 35 x 107 mol of argon 40 how much potassium 40 would also have to be present for the rock 1 3 x 10 years old The half life of K 40 is 1 3 x 10 years i mol K 40

Which of the following is an ionic compound OH S O NH3 O 1 OKI CCL

Consider the following quilibrium 200 200 TO 2008 The equilibrium constant kc 0 00000052 If the initial concentrativne per CO is 0 0023 M what is the equilibrium concentration for Co in M WHO

Which of the following elements has the largest first ionization energy O Na CO CI O Ca O Te O Br

Question 5 Which statement about the retention factor of a component in a mixture is not correct O The retention factor increases if the partition constant of the component increases O The retention factor is the ratio of the time a component spends in the mobile phase relative to the time it spends in the stationary phase The retention factor should ideally be between 1 and 5 The retention factor gives an indication of how well the component will be resolved from other components in the mixture All these statements are correct Figure 5

Select the most polar bond amongst the following O C O O Si F O CI F O C F SO C I

Select the element with the greatest metallic character O Li O Ca SO AI O Pb

Chemistry What controls the mobile phase flow rate in ascending TLC or paper chromatography Do you think it is constant during the separation

Select the correct electron configuration for Te Z 52 O kr 5s 5p64d8 O kr 5s25d 05p4 O kr 5s24d 05p6 O kr 5s24f14 O kr 5s 4d 05p

a b Castag H O H O PRACTICE c If possible write dissociation equations for the six compc shown in the photograph Otherwise write no dissociati H O a NiCl aq b KMnO4 aq c CuSO aq d Pb NO3 2 aq e AgCl aq H O H O c H O d e f

14 Determine the volume of 0 25 M NaHCO3 needed to react with 5 0 g of H SO4 and produ Na2SO4 CO2 and H O The unbalanced equation is NaHCO3 H SO4 Na2SO4 H O CO