General Questions and Answers

What is the quantum symbol for the spin momentum and what does it represent

hat is the mass in g of 0 935 mol of acetone CH3COCH The molar mass of acetone is 58 08 g mol C A 0 0161 g B 54 3 g C 57 1 g D 62 1 g 50 F 8 58 PM 5 3 2022

The change in temperature from 10 C to 20 C is found to double the rate of particular chemical reaction How did the change in temperature affect the reaction Y A The number of molecules colliding with sufficient energy to react increased B The number of molecules colliding with sufficient energy to react decreased C The activation energy increased D The activation energy decreased

late electron configuration for the phosphide ion P3 A Ne 3s B Ne 3s 3p3 C Ne 3p D Ne 3s 3p6 Im 49 F A 9 42 PM 5 3 2022 5

solution was made by adding 800 g of ethanol C H5OH to What is the w w C H5OH A 9 1 B 10 C 91 D 99

Which molecule has polar bonds but is overall nonpolar A H S B O C SO D SO3

If a student used a 1 5 ml of a 2M solution of BH3 in THF density of 0 876 g ml What is the mass in grams of the solution used Please show calculations

The most probable distribution in any system is characterized by having Select the correct answer below O maximal entropy minimal entropy O the fewest particles O the fewest microstates

Which two functional groups are in the molecule shown below Use the terms left and right to distinguish them H O The left functional grou right functional ge

What functional group is highlighted in this section of an unknown drug Cl H The highlighted functional group is a ketc

Which of the following is the definition of a distribution as it relates to the microstates of a system Select the correct answer below the total number of microstates for the system O a group of microstates with equivalent particle arrangements the microstate of a system that has maximal entropy the microstate of a system that has minimal entropy

5 2 points One of the product of neutralization reaction is salt True False St Preous

nich sample has the largest volume The density of aluminum is 2 7 g mL and the density of copper is 9 0 g mL A 1 0 g aluminum B 5 0 g aluminum C 1 0 g copper D 5 0 g copper

Which of the following indicates the highest pressure Select one O a 145 000 Pa O b 1 00 atm O c O d 316 mm Hg 801 torr Oe 1 00 bar

g of KCI s is required to prepare 607 2 mL of 0 422 M KCI aq solution Please report mass to 3 significant figures

13 2 points Heat is the transfer of thermal energy between two bodies at different temperature True False

During a reaction involving the formation of a complex ion which of the following is true when Q K Select the correct answer below The formation of the complex ion will quickly come to a halt The reactants will be favored The complex ion will dissociate into its constituent ions More of the complex ion will form

Calculate the standard free energy change for the reaction at 25 C Refer to the list of standard reduction potentials 3 2 Au aq 3 Ni s 2 Au s 3 Ni aq

Based on the sign of the standard cell potential Ecell classify these reactions as spontaneous or nonspontaneous as written Assume standard conditions Refer to the list of standard reduction potentials Spontaneous as written Answer Bank Nonspontaneous as written

Two identical gas cylinders have equivalent volumes and are filled to the same total pressure at the same temperature One cylinder is filled with pure O2 g The other cylinder is filled with an oxygen xenon gas mixture with Xo2 0 25 and Xxe 0 75 Which of the following statements is true Select one O a the mixed gas sample weighs more than the oxygen sample O b the oxygen sample weighs more than the mixed gas sample O c the two gas samples contain equivalent moles of O2 g O d the two gas samples weigh the same

2 points Reducing agent provides electrons to the oxidizing agent True False

2 points Form the following chemical equation identify the oxidizing agent and reducing agent K P s 20 g K3PO4 s a Reducing Agent Oxidizing Agent

20 2 points The IUPAC standard state is the conditions referring to materials under a pressure of 1 bar and solutions at 1 molar concentration True False

Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass Count the number of atoms of each element in K SO4 Tap in the fields to enter the answers directly OR tap on the Number Pad icon to use our built in Number Pad Potassium K dimensions you prefer Sulfur S Oxygen 0 Tap Vi

30 5 points What mass in g of aluminum molar mass 26 98 g mol would be required to completely react with 5 29 L of 0 463 M HCl in the following chemical reaction 2 Al s 6HCl aq 2 AlCl3 aq 3 H g Answer to 1 decimal place Type your answer

27 5 points A 58 1 mL sample of a 0 101 M potassium sulfate solution is mixed with 39 7 mL of a 0 120 M lead II acetate solution and this precipitation reaction occurs K SO4 aq Pb C2H3O2 2 aq 2 KC 2H3O2 aq PbSO4 s The solid PbSO4 molar mass 303 26 g mol is collected dried and found to have a mass of 1 02 g Determine the theoretical yield in grams Answer to 2 decimal places Type your answer

2 points A substance dissolves in water to give yield hydroxide ions is a base True False Sh Pres hus

21 2 points Choose the coefficients the would balance the following chemical reaction a CH4 b Br2 c CBr2 d HBr b d

23 2 points Determine the oxidation state of phosphorous in the following compound K3PO3 Type your answer

26 5 points Molecular iodine 12 Molar mass 253 81 g mol is produced by the reaction of 8 13 g of CuCl2 Molar mass 134 45 g mol according to the following equation 2 CC2 4K 2 Cul 4 KCI 1 How many grams of l2 is produced Answer to 2 decimal places Type your answer

2 points If a process can be written as the sum of several stepwise processes the enthalpy change of the total process equals the product of the enthalpy changen True False revious

Place each reactions in the correct category a Pb NO3 2 aq H SO4 aq PbSO4 s 2 HNO3 aq b 2 Na s 2 HCl aq 2 NaCl aq H g c Mg s NiCl aq MgCl2 aq Ni s d 3 KOH aq H PO4 aq Precipitation reaction Oxidation reaction Possible answers K3PO4 aq 3 H O l No Answers Chosen No Answers Chosen a Neutralization reaction No Answers Chosen

28 5 points When 3 98 g of bismuth oxide molar mass 465 96 g ml reacts with excess carbon to form 2 97 g of bismuth metal molar mass 208 98 g mol according to the equation Bi2O3 s 3 C s 2 Bi s 3 CO g What is the percent yield of the reaction Answer to 1 decimal place Type your answer

Expansion work occurs when a system push back the surrounding against a restraining pressure True False

Heat of Formation practice e 1 Calculate AH for the following reactions using the heats of formation remember all diatomics and single elements are 0 kJ mol a 8Al s 3Fe3O4 s 4Al2O3 s 9Fe s AH 4 mol A1 203 1669 kg mol 9 mol Pe 0 kg mol 8 nol A1 0 3 mol Fe204 1670 c4 x 1669 9x 8x0 3x1670 11 686 kJ mol b CO g O2 g CO2 g AH 4x 393 5 4x 110 5 4x 110 692 kJ mol c C H2 g H2 g C2H4 8 OH 52 45 226673 217 d NH3 g O2 g NO g H O g KCI 0 KClO3 391 28 kg mol

35 5 points Determine the enthalpy of reaction in kJ for HCI g NaNO s HNO2 1 NaCl s Given the following thermochemical equations 2NaCl s H O l 2HCI g Na O s AH 507 1 kJ NO g NO g Na O s 2NaNO s AH 427 0 kJ NO g NO g N O g O g AH 43 01 kJ 2HNO 1 N O g O g H O 1 AH 34 02 kJ Answer to 1 decimal place ur answer

31 5 points Suppose a certain material has a specific heat of 0 864 J g C If 4 19 kJ of heat is applied to 344 3 g of the material at 25 2 C what is the final temperature in C of the material Answer to 1 decimal place Type your answer

2 2 points The net ionic equation would contain only the spectator ions True False

The number of protons IS the Atomic Number the sum of protons ADDED to the neutrons Mass number can vary for the same element if the element has different numbers of neutrons When this happens these forms of an element are called isotopes

The reactant in the oxidation half reaction is the oxidizing agent True False

dissolve dissolving dissociate dissociation ionize ionization B Iron III chlorate dissolves in water If you dissolve 2 5 x 106 formula units of Iron III chlorate in a 500 mL of water determine the number of ions that will be contained in the solution C Hydrogen combined with the halogens and some polyatomic anions to produce compounds that ionize in water that they dissolve to form ions For example hydrogen chloride HCI when dissolved in water the molecule of HCI dissociat into H cation called Hydronium ion and Cl chloride ion making a solution that is acidic The H ion is what makes the solution acidic and the solution is known as hydrochloric acid If you have 4 5 x 1015 molecules of HCI and mix it with w determine the number of H ion contained in the solution made 2 Reactivity of Metals and a reactivity series

1 point A unit conversion factor is the ratio of two equivalent quantities expressed with different measurement units O True False

1 point A balanced chemical equation must have the equal number of reactant and product molecules True False

point Hydrocarbons are compounds containing hydrogen oxygen and carbon True False

2 1 point The precision of measurements associates with the closeness to the true value of the property being measured O True False

1 point A mole is defined as the amount of substance containing the same number of discrete rntities as the number of atoms in a sample of pure 12C weighing exactly 12 True False

8 1 point Reducing agent provides electrons to the oxidizing agent True False

25 1 point A standard enthalpy of formation is an enthalpy change for a reaction in which exactly 1 mole of a pure substance is formed from free elements in their most stable states standard state conditions True False Breidaus

6 1 point The amount of product calculated per the stoichiometry of an appropriate balanced chemical equation is called the actual yield True False 200

1 point The property of matter that gives the distinct characteristic associates with a substance s state of matter is a chemical property O True False