CHEM 31513 | Course Paper

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Which of the following regions of the electromagnetic spectrum has the lowest

frequency?

A.x-ray

B.gamma ray

C.ultraviolet

D.infrared

E.visible

What is the freezing point of a solution containing 2.80 grams benzene (molar mass =

78.11 g/mol) dissolved in 43.0 grams paradichlorobenzene (molar mass = 147.0 g/mol)?

The freezing point of pure paradichlorobenzene is 53.0 C and the freezing point

depression constant, Kfp, is “7.10 C/m.

A.46.7 C

B.47.1 C

C.58.9 C

D.52.6 C

E.58.9 C

Ammonium perchlorate can decompose violently according to the chemical equation

below.

2 NH4ClO4(s) N2(g) + Cl2(g) + 2 O2(g) + 4 H2O(g)

What volume of chlorine gas is produced by the decomposition of 120 g NH4ClO4 at

650 K and 1.0 atm? (R = 0.08206 Latm/Kmol)

A.27 L

B.54 L

C.91 L

D.110 L

E.3200 L

Write a balanced chemical equation for the reaction of aqueous solutions of magnesium

chloride and potassium phosphate.

A.MgCl2(aq) + K3PO4(aq) K3Mg(s) + PO4Cl2(aq)

B.3 MgCl2(aq) + 2 K3PO4(aq) 3 K2Mg(s) + 2 PO4Cl3(aq)

C.MgCl(aq) + KPO4(aq) MgPO4(s) + KCl(aq)

D.MgCl2(aq) + 2 KPO4(aq) Mg(PO4)2(s) + 2 KCl(aq)

E.3 MgCl2(aq) + 2 K3PO4(aq) Mg3(PO4)2(s) + 6 KCl(aq)

Which of the following statements are CORRECT?

1/ Chili saltpeter is a common name for NaNO3.

2/ Trona is a common name for Na2CO3NaHCO32 H2O.

3/ Soda ash is a common name for Na2CO3.

A.1 only

B.2 only

C.3 only

D.1 and 3

E.1, 2, and 3

For a reaction, A B + C, which of the following equations corresponds to the integrated

expression for a second-order decomposition reaction?

Calculate the enthalpy change (DrH) for the reaction below,

N2(g) + 3 F2(g) 2 NF3(g)

given the bond enthalpies of the reactants and products.

Bond Bond Enthalpy

(kJ/molrxn)

N-N 163

N=N 418

NN 945

F-F 155

N-F 283

A.”288 kJ

B.”1070 kJ

C.”637 kJ

D.+288 kJ

E.+293 kJ

What class of compounds is responsible for many of the distinctive odors of artificial

flavors and perfumes?

A.ethers

B.aldehydes

C.esters

D.amides

E.alkenes

For which one of the following molecules do geometric isomers exist?

A.H2ClC-CHCl2

B.BrHC=CHBr

C.ClCCH

D.H3C-CH2Cl

E.H2C=CCl2

What are the approximate F-Br-F bond angles in BrF5?

A.90 and 180

B.109.5

C.90 and 120

D.120

E.180

Which of the following liquids has the largest enthalpy of vaporization?

A.C5H12

B.C4H10

C.C3H8

D.C2H6

E.C6H14

What is the pH of a solution that results from diluting 0.30 mol acetic acid (CH3CO2H)

and 0.20 mol sodium acetate (NaCH3CO2) with water to a volume of 1.0 L? (Ka of

CH3CO2H = 1.8 10“5)

A.4.35

B.4.57

C.4.74

D.4.92

E.5.14

Which of the following properties is associated with the value of the quantum

number?

A.the shape of an orbital

B.the size of an orbital

C.the number of electrons in an orbital

D.the energy of an orbital

E.the orientation in space of an orbital

Catalytic steam reformation of hydrocarbons (such as methane) produce a mixture of

A.CO2 and H2O.

B.C and H2.

C.O2 and H2.

D.CH4 and H2O.

E.CO and H2.

The reaction of coal and water at a high temperature produces a mixture of hydrogen

and carbon monoxide gases. This mixture is known as synthesis gas (or syngas). What

mass of water is required for the formation of 175 grams of carbon monoxide?

C(s) + H2O(g) H2(g) + CO(g)

A.272 g

B.315 g

C.489 g

D.113 g

E.175 g

At a high temperature, equal concentrations of 0.160 mol/L of H2(g) and I2(g) are

initially present in a flask. The H2 and I2 react according to the balanced equation

below.

H2(g) + I2(g) 2 HI(g)

When equilibrium is reached, the concentration of H2(g) has decreased to 0.036 mol/L.

What is the equilibrium constant, Kc, for the reaction?

A.3.4

B.4.0

C.12

D.22

E.48

Iron, _____, and sulfur form the reactive portion of nitrogenase, a biological catalyst

used by nitrogen-fixing organisms.

A.Fe

B.Co

C.Zn

D.Cd

E.Mo

What is the hybridization of the central iodine atom in I3

“?

A.sp

B.sp2

C.sp3

D.sp3d

E.sp3d2

What is the minimum mass of ice at 0.0 C that must be added to 1.00 kg of water to

cool the water from 28.0 C to 12.0 C? (Heat of fusion = 333 J/g; specific heat

capacities: ice = 2.06 J/gK, liquid water = 4.184 J/gK)

A.175 g

B.201 g

C.244 g

D.299 g

E.1140 g

According to the effective atomic number rule, Ru(0) should coordinate to ____

carbonyl ligands.

A.4

B.5

C.6

D.7

E.8

Which of the following molecules is expected to form hydrogen bonds in the pure

liquid or solid phase: ethanol (CH3CH2OH), acetic acid (CH3CO2H), acetaldehyde

(CH3CHO), and dimethyl ether (CH3OCH3)?

A.ethanol only

B.acetaldehyde only

C.ethanol and acetic acid

D.acetaldehyde and dimethyl ether

E.ethanol and dimethyl ether

Niobium crystallizes in a body-centered cubic unit cell. If the radius of a niobium atom

is 0.145 nm, what is the length of an edge of the unit cell?

A.0.251 nm

B.0.290 nm

C.0.335 nm

D.0.410 nm

E.0.502 nm

Which molecule will have the following valence molecular orbital energy level

diagram?

s*2p

p*2p

s2p

p2p

s*2s

s2s

A.Be2

B.B2

C.C2

D.N2

E.O2

If the reaction quotient, Q, is equal to K in a gas phase reaction, then

A.the chemical system has reached equilibrium.

B.the temperature must be increased for the reaction to proceed in the forward

direction.

C.the reaction will proceed in the forward direction until equilibrium is established.

D.the reaction will proceed in the backward direction until equilibrium is established.

E.the reaction will proceed in the direction that increases the number of gas phase

particles.

What is the general formula for an alkane?

A.CnH2n+2

B.CnH2n

C.CnHn“2

D.Cn+2Hn

E.CnH2n“2

You have 2.50 g of each of the following elements: Ca, Cu, Cs, C, and Cr. Which

sample contains the largest number of atoms?

A.Ca

B.Cu

C.Cs

D.C

E.Cr

What is the total number of orbitals having n = 4 and = 2?

A.3

B.5

C.7

D.9

E.10

Convert 0.490 ng to milligrams and express the answer in scientific notation using the

correct number of significant figures.

A.4.90 10“5 mg

B.4.90 10“7 mg

C.4.9 10“7 mg

D.0.490 10“8 mg

E.0.490 10“7 mg

For which of the following reactions will the entropy of the system decrease?

A.2 NH3(g) N2(g) + 3 H2(g)

B.2 C(s) + O2(g) 2 CO(g)

C.CaCO3(s) CaO(s) + CO2(g)

D.2 NO2(g) N2O4(g)

E.NaOH(s) Na+(aq) + OH“(aq)

If two or more species have the same number of electrons, resulting in similar Lewis

structures, they are said to be ____.

A.isoelectronic

B.resonant structures

C.ionic

D.neutral

E.covalent