Cem 82231 | Course Paper

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How many joules are equivalent to 450 calories?

A.0.45 J

B.4.5 102 J

C.9.3 10“3 J

D.1.9 103 J

E.4.5 105 J

Which of the following statements concerning sodium and potassium is/are

CORRECT?

1/ The sodium concentration in seawater is over three times greater than the

concentration of potassium.

2/ Plants contain roughly four to six times more sodium than potassium.

3/ Roman soldiers were paid in sodium chloride.

A.1 only

B.2 only

C.3 only

D.1 and 3

E.1, 2, and 3

Which of the following properties of water can be attributed to hydrogen bonding?

1/ high melting point

2/ high heat of vaporization

3/ low vapor pressure

4/ high surface tension

A.1 and 3

B.2 and 3

C.2, 3, and 4

D.1, 3, and 4

E.1, 2, 3, and 4

At what pH will an aqueous solution of 0.200 M Ni2+ begin to precipitate as Ni(OH)2 at

25 C? The Ksp of Ni(OH)2 is 5.5 10“16 at 25 C.

A.6.37

B.6.72

C.7.28

D.7.63

E.7.93

Polyvinyl chloride is used in raincoats and pipes. It is produced by the addition reaction

of chloroethylene, CH2CHCl. What is the structure of the polymer produced in this

reaction?

Calcium sulfide has a face-centered cubic unit cell with calcium ions in octahedral

holes. How many ions of each element are contained in each unit cell?

A.1 calcium ions; 1 sulfide ions

B.2 calcium ions; 2 sulfide ions

C.2 calcium ions; 4 sulfide ions

D.4 calcium ions; 2 sulfide ions

E.4 calcium ions; 4 sulfide ions

The following valence molecular orbital energy level diagram is appropriate for which

one of the listed species?

s*2p

p*2p

s2p

p2p

s*2s

s2s

A.B2

B.C2

C.N2

D.O2

E.F2

How many structures (i.e., unique isomers) exist for tribromobenzene?

A.2

B.3

C.4

D.5

E.6

The central atom in N2O is a nitrogen atom. This nitrogen atom is surrounded by

A.two single bonds and two lone pairs of electrons.

B.two single bonds and one lone pair of electrons.

C.one single bond, one double bond, and one lone pairs of electrons.

D.one single bond, one double bond, and one lone pair of electrons.

E.two double bonds and no lone pairs of electrons.

Which of the following statements concerning a metal crystallized in a face-centered

cubic cell is/are CORRECT?

1/ One metal atom is located on each face of the unit cell, where it is shared equally

between four unit cells.

2/ One metal atom is located at the center of the unit cell.

3/ A metal atom is located at each of the eight lattice points, where it is shared equally

between eight unit cells.

A.1 only

B.2 only

C.3 only

D.1 and 3

E.1, 2 and 3

Excess Ag2SO4(s) is placed in water at 25 C. At equilibrium, the solution contains

0.029 M Ag+(aq). What is the equilibrium constant for the reaction below?

Ag2SO4(s) 2 Ag+(aq) + SO4

2″(aq)

A.1.8 10“7

B.6.1 10“6

C.1.2 10“5

D.2.4 10“5

E.8.4 10“4

The thermochemical equation for the combustion of butane is shown below.

C4H10(g) + 13/2 O2(g) 4 CO2(g) + 5 H2O( ) DrH = “2877 kJ/mol-rxn

What is the enthalpy change for the following reaction?

8 CO2(g) + 10 H2O( ) 2 C4H10(g) + 13 O2(g)

A.+1439 kJ/mol-rxn

B.+2877 kJ/mol-rxn

C.”5754 kJ/mol-rxn

D.”2877 kJ/mol-rxn

E.+5754 kJ/mol-rxn

For the second-order reaction below, the rate constant of the reaction is 9.4 10“3 M“1s“1.

How long (in seconds) is required to decrease the concentration of A from 2.16 M to

0.40 M?

2A B rate = k[A]2

A.2.0 101 s

B.7.8 101 s

C.1.8 102 s

D.1.9 102 s

E.2.2 102 s

Which of the following statements is/are CORRECT?

1/ A nickel-cadmium battery is an example of a secondary or rechargable battery, often

used in rechargable cordless appliances.

2/ Hydrogen-oxygen fuel cells use the heat of combustion of hydrogen to recharge lead

storage batteries.

3/ LeClanch cells are the most efficient rechargable batteries, but they are rarely used

due their high cost of production.

A.1 only

B.2 only

C.3 only

D.1 and 3

E.1, 2, and 3

If 0.10 M aqueous solutions are prepared of each of the following acids, which

produces the solution with the lowest pH?

A.benzoic acid, Ka = 6.3 10“5

B.acetic acid, Ka = 1.8 10“5

C.hydrocyanic acid (HCN), Ka = 4.0 10“10

D.hydrogen sulfite ion (HSO3

–), Ka = 6.2 10“8

E.hypobromous (HOBr), Ka = 2.5 10“9

What is the pH of 3.5 10-3 M HCl(aq)?

A.”1.01

B.2.46

C.3.50

D.1.01

E.5.65

All of the following statements concerning sodium are correct EXCEPT

A.most sodium compounds are water soluble.

B.sodium is soft and easily cut with a knife.

C.sodium is usually found in nature as the reduced metal or as a sulfide salt.

D.sodium ions help regulate osmotic pressure in the human body.

E.sodium is commercially prepared by electrolysis of molten NaCl.

If a nucleus emits an alpha particle

A.its atomic number decreases by four and its mass number decreases by two.

B.its atomic number decreases by two and its mass number decreases by four.

C.its atomic number increases by two and its mass number decreases by two.

D.its atomic number is unchanged and its mass number is unchanged.

E.its atomic number is unchanged and its mass number decreases by four.

For the reaction below, if the rate of appearance of Br2 is 0.180 M/s, what is the rate of

disappearance of NOBr?

2 NOBr(g) 2 NO(g) + Br2(g)

A.”0.360 M/s

B.”0.090 M/s

C.0.090 M/s

D.0.180 M/s

E.0.720 M/s

What volume of 0.250 M KCl(aq) will completely react with 50.0 mL of 0.115 M

Pb(NO3)2(aq)?

2 KCl(aq) + Pb(NO3)2(aq) PbSO4(s) + 2 KNO3(aq)

A.23.0 mL

B.46.0 mL

C.11.5 mL

D.109 mL

E.218 mL

Tin melts at 232.0 C. What is this temperature in kelvin?

A.”41.2 K

B.232.0 K

C.449.6 K

D.505.2 K

E.530.2 K

Silver chloride (AgCl) is relatively insoluble in water. At 25 C, 1.3 103 L of water is

needed to dissolve 2.5 g of AgCl. What mass (in milligrams) of AgCl will dissolve in

1.0 L of water?

A.1.9 10“3 mg

B.1.9 mg

C.0.52 mg

D.520 mg

E.1.9 10“6 mg

Potassium crystallizes in a body-centered cubic unit cell. If the length of an edge of the

unit cell is 524 pm, what is the atomic radius (in pm) of a potassium atom?

A.151 pm

B.185 pm

C.227 pm

D.262 pm

E.371 pm

What is the equilibrium constant for the following reaction,

HCO2H(aq) + CN“(aq) HCO2

“(aq) + HCN(aq)

and does the reaction favor the formation of reactants or products? The acid

dissociation constant, Ka, for HCO2H is 1.8 10“4 and the acid dissociation constant for

HCN is 4.0 10“10.

A.K = 1.00. The reaction favors neither the formation of reactants nor products.

B.K = 2.2 10“6. The reaction favors the formation of products.

C.K = 2.2 10“6. The reaction favors the formation of reactants.

D.K = 4.5 105. The reaction favors the formation of products.

E.K = 4.5 105. The reaction favors the formation of reactants.

For a chemical system, DrG and DrG are equal when

A.the system is in equilibrium.

B.the reactants and products are in standard state conditions.

C.the equilibrium constant, K, equals 0.

D.the reaction quotient, Q, is less than 1.

E.the reactants and products are in the gas phase.

Anhydrous hydrogen fluoride is used in all of the following applications EXCEPT

A.etching fluorescent light bulbs.

B.the production of refrigerants.

C.the reduction of alkali and alkaline earth metals.

D.the production of plastics.

E.the production of herbicides.

What is the name of the compound having the formula [Cr(en)2(H2O)2]SO4?

A.dihydroxydiethlyenediamminechromate(II) sulfate

B.diaquabis(ethylenediamine)sulfatochromate(IV)

C.bis(ethylenediamine)diaquachromium(II) sulfato

D.diaquabis(ethylenediamine)sulfatochromium(II)

E.diaquabis(ethylenediamine)chromium(II) sulfate

When 66.0 g of an unknown metal at 28.5 C is placed in 83.0 g H2O at 78.5 C, the

water temperature decreases to 75.9 C. What is the specific heat capacity of the metal?

The specific heat capacity of water is 4.184 J/gK.

A.0.055 J/gK

B.0.29 J/gK

C.0.69 J/gK

D.0.18 J/gK

E.2.6 J/gK

Freon-113, C2Cl3F3, has an enthalpy of vaporization of 27.0 kJ/mol and a normal

boiling point of 48.0 C. What is the vapor pressure (in atm) of Freon-113 at 22.0 C? (R

= 8.314 J/Kmol)

A. 0.21 atm

B. 0.35 atm

C. 0.41 atm

D. 0.46 atm

E. 4.4 atm

All of the following are colloidal dispersions EXCEPT ____.

A.marshmallow

B.white wine

C.milk

D.whipped cream

E.cheese

The equilibrium constant at 25 C for the dissolution of silver iodide is 8.5 10“17.

AgI(s) Ag+(aq) + I“(aq)

If an excess quantity of AgI(s) is added to water and allowed to equilibrate, what is the

equilibrium concentration of I“?

A.7.2 10“33 M

B.4.3 10“17 M

C.8.5 10“17 M

D.6.5 10“9 M

E.9.2 10“9 M

The equilibrium constant, Kc, for the decomposition of ammonium hydrogen sulfide is

1.8 10“4 at 25 C.

NH4HS(s) NH3(g) + H2S(g)

If excess NH4HS(s) is allowed to equilibrate at 25 C, what is the equilibrium

concentration of NH3?

A.3.2 10“8 M

B.9.0 10“5 M

C.1.8 10“4 M

D.6.7 10“3 M

E.1.3 10“2 M