Chem 1320 Final Review - Old Test Questions

What is the formula of the compound formed when ammonium ions react with chromate ions?

(NH4)2CrO4

Assign a formal charge to the chlorine atom in the structure.

+1

What is the oxidation number of the sulfur atom in FeSO4?

+6

Using the table of standard formation enthalpies provided, calculate the reaction enthalpy of this reaction under standard conditions: 2 C2H6 + 7 O2 -> 4 CO2 + 6 H2O C2H6: -84 O2: 0 CO2: -393.5 H2O: -285.8

-3121. kJ

Using appropriate bond energies, calculate the heat of reaction /\H for the following reaction: H | 2 H-H + O=O -> 2O-H Relevant bond energies (kJ/mol): H-H 436 H-O 497 O=O 498

-618 kJ/mol

Consider the following balanced chemical equation: 2 C8H18 + 25 O2 -> 16 CO2 + 18 H2O What is the theoretical yield of water (molar mass = 18.02) is formed from the reaction of 2.3 g of C8H18 (molar mass = 114.2) and 2.0 g of O2 (molar mass = 32.00)?

0.81 g

A tank is filled with 5.02 g of chlorine pentafluoride gas (molar mass = 130.44) and 12.3 g of carbon dioxide gas (molar mass = 44.01). You can assume both gases behave as ideal gases under these conditions. Calculate the mole fraction of carbon dioxide in this mixture.

0.879

Which angular momentum quantum number corresponds to the 5p subshell?

1

A student sets up the following equation to convert a measurement. Fill in the missing conversion of this equation. (58 J/mol) * _____ = kJ/mol

1 kJ/ 10^3 J

Calculate the volume in liters of a 0.645 M iron (III) bromide solution that contains 200. g of iron (III) bromide (molar mass = 295.55 g).

1.05 L

A chemistry student must write down in her lab notebook the concentration of a solution of sodium hydroxide. The concentration of a solution equals the mass of what's dissolved divided by the total volume of the solution. Here's how the student prepared the solution: The label on the graduated cylinder says: empty weight: 4.500 G She put some solid sodium hydroxide into the graduated cylinder and weighed it. With the sodium hydroxide added, the cylinder weighed 34.1 g. She added water to the graduated cylinder and dissolved the sodium hydroxide completely. then she read the total volume of the solution from the markings on the graduated cylinder. The total volume of the solution was 26.11 mL. What concentration should the student write down in her lab notebook? Be sure your answer has the correct number of significant digits.

1.12 g/mL

A reaction between liquid reactants takes place at 255.15 K in a sealed, evacuated vessel with a measured volume of 5.0 L. Measurements show that the reaction produced 0.3297 mol of chlorine pentafluoride gas. Calculate the pressure of chlorine pentafluoride gas in the reaction vessel after the reaction. you may ignore the volume of the liquid reactants.

1.4 atm

A tablespoon of corn oil has an energy content of 14.0 kcal. What is this energy content expresses in cal?

1.40 x 10^4

Calculate the number of nitrogen atoms in a 140.0 g sample of dinitrogen tetroxide (N2O4).

1.833 x 10^24

A chemist measures the enthalpy change during the following reaction: C6H12O6 (s) -> 2 CO2 (g) + 2 C2H5OH (l) /\H = -69. kJ Use this information to calculate the enthalpy change for the following: 4 CO2 (g) + 4 C2H5OH (l) -> 2 C6H12O6 (s)

138. kJ

A chemist must prepare 200. mL of 2.00 M aqueous sodium chloride working solution. He'll do this by pouring out some 2.09 M aqueous sodium chloride stock solution into a graduated cylinder and diluting it with distilled water. Calculate the volume in of the sodium chloride stock solution that the chemist should pour out.

191. mL

Balance the chemical equation below using the smallest possible whole number stoichiometric coefficients. When the equation is properly balanced, what is the coefficient for Na in this equation? Na + O2 -> Na2O2

2

How many bonding pairs are around the oxygen atom in H2O?

2

The vapor pressure of mercury at 25 C is 1.85 torr. Calculate the vapor pressure in 1 atm.

2.43 x 10^-3 atm

A chemist needs to know the mass of a sample of potassium sulfate to 2 significant digits. He puts the sample on a digital scale. This is what the scale shows: 0.26.473 g. If this measurement is precise enough for the chemist, round it to 2 significant digits.

26.

How many significant digits are in the following measurement? 0.001100 J

4

Fice samples of xenon gas are described int he table below. Select the sample that has the lowest kinetic energy. A - Amount: 1.3 mol; Pressure: 2.1 atm; Temperature: -12 C B - 2.3 mol; 2.8 atm; 2 C C - 2.4 mol; 1.9 atm; -22 C D - 1.0 mol; 1.3 atm; 1 C E - 2.8 mol; 1.6 atm; -7 C

C

Which of the following ionizations would require the least amount of energy? Br -> Br+ + e- Ne -> Ne+ + e- Rb -> Rb+ +e-

Rb -> Rb+ +e-

Which of the following statements is true? - RbBr has a greater lattice energy than CsBr and CaCl2 has a greater lattice energy than CaS. - RbBr has a greater lattice energy than CsBr and CaS has a greater lattice energy than CaCl2. - CsBr has a greater lattice energy than RbBr and CaS has a greater lattice energy than CaCl2. -CsBr has a greater lattice energy than RbBr and CaCl2 has a greater lattice energy than CaS.

RbBr has a greater lattice energy than CsBr and CaS has a greater lattice energy than CaCl2.

Select the symbol for the ion that an atom of sulfur is most likely to form.

S 2-

Which of the following species does not have exactly 18 electrons? Ar S- K+ Cl- Ca+2

S-

The first five ionization energies of a Period 3 element have the following patter: huge jump between IE4 and IE5

Si

Consider the following molecules. Which statement is correct concerning the energy of the bonds in these molecules? .. .. .. H - N - H H - As - H H - P - H | | | H H H

The N-H bonds have the highest energy, the As-H bonds have the lowest energy.

Which structure is reasonable for CHO2 - ?

A, D

Which of the following types of radiation has the longest wavelength?

radio waves

What type of orbital is this?

s orbital

What is the hybridization of the central atom in BrO4 - ?

sp^3

What phrase best describes the arrangement of electron groups around the central phosphorous atom in the phosphorous trichloride (PCl3) molecule?

tetrahedral

Classify the following chemical reaction: 2 Ch3(CH2)2CH3 (g) + 13 O2 (g) -> 8 CO2 + 10 H2O

combustion

Name Cl2O7.

dichlorine heptoxide

Which word best describes the shape of the CO2 molecule?

linear

An atomic cation with a charge of +2 has the following electron configuration: 1s^2 2s^2 2p^6 3s^2 3p^4 What is the chemical symbol for the ion?

Ar +2

The following chemical reaction takes place in aqueous solution: AgF (aq) + NH4I (aq) -> AgI (s) + NH4F (aq)

Ag+ (aq) + I- -> AgI (s)

A chemical reaction takes place inside a flask submerged in a water bath. The water bath contains 3.60 x 10^3 g of water at 37.3 C. During the reaction 85.5 x 10^3 J of heat flows out of the flask and into the bath. Calculate the new temperature of the water bath. you can assume the specific heat capacity of water under these conditions is 4.18 J/g*K.

43.0 C

Which of the following subshells has the highest energy? 1s 3d 5s 4d 4p

4d

An arctic weather balloon is filled with 6.73 L of helium gas inside a prep shed. The temperature inside the shed is 13 C. The balloon is then taken outside, where the temperature is -42 C. Calculate the new volume of the balloon. You may assume the pressure remains constant at exactly 1 atm.

5.44 L

Ammonia reacts with water according to the following balanced chemical equation: 4 NH3 + 5 O2 -> 4 NO + 6 H2O If 4.09 g of ammonia (molar mass = 17.03) react in the presence of excess oxygen, what mass of water (molar mass = 18.02) is produced?

6.49 g

A chemist prepares a solution of sodium carbonate by measuring out 3.17 umol (micromol) of sodium carbonate into a 50. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in umol/L (micromol per liter) of the chemist's sodium carbonate solution.

63. umol/L

Which statement describes the reaction? Electron affinity = 101.3 kJ/mol and ionization energy = 710.2 kJ/mol

710.2 kJ/mol is absorbed

A cup of cook white rice has an energy content of 225 kcal. What is this energy content in kJ?

941. kJ

Which is not the symbol for a chemical element that has atomic number less than 13 and atomic mass greater than 15.7 u. N, Ne, Na, O, F

N

For which of the following atoms would a valence electron experience the greatest effective nuclear charge, Z*? Be, B, Ne, N, C

Ne

Which of the following shows the list of elements in order of decreasing electronegativity? Te, O, Se Se, O, Te Te, Se, O O, Te, Se O, Se, Te

O, Se, Te

Predict the product (besides water) that forms when chloric acid reacts with calcium hydroxide.

Ca(ClO3)2

What is the "AXE" description of the carbon in the methanone (H2CO) molecule?

AN3E0

What is the polarity of the ClF, CO2, and SiF4 molecules?

ClF is polar, CO2 and SiF4 are nonpolar

Which of the following compounds is molecular? -H2SO3 -SNCO3 -BaBl2 -AlCl3 -MgI2

H2SO3

Order the following species according to size, with the largest fist and the smallest last: Al, Al +2, Mg

Mg, Al, Al +2

Regarding the structure, which statement is true? .. .. H - C = N - The structure is reasonable. - The structure had the wrong number of valence electrons. The correct number is 12. - The structure has the right number of valence electrons but doesn't satisfy the octet rule. The symbol of the problem atom is N.

The structure has the right number of valence electrons but doesn't satisfy the octet rule. The symbol of the problem atom is N.

Regarding the structure, which statement is true? PF4 - - The structure is reasonable. - The structure had the wrong number of valence electrons. The correct number is 32. - The structure has the right number of valence electrons but doesn't satisfy the octet rule. The symbol of the problem atom is P.

The structure is reasonable.

Select the formula of the ionic compound formed by reacting Zn +2 with F -.

ZnF2

Which of the following neutral atoms have an outer electron configuration of ms^2nd^2 where n and m are integers, and m = n + 1? Zr, Ba, Ge, Sc, Cr

Zr