Chemistry Final Exam

ive the stoichiometric coefficient for oxygen when the following equation is balanced using the lowest, whole-number coefficients. _____ C H4O ( l) + _____ O2 (g) → _____ CO2 ( g) + _____ H2O (l)

3

How many anions are there in 0.500 g of MgBr2?

3.27 × 1021 anions

Electromagnetic radiation with a wavelength of 575 nm appears as yellow light to the human eye. Calculate the energy of one photon of this light.

3.46 × 10-19 J

How many cm 3 are contained in 3.83 × 10 7 mm

3.83 × 10^4 cm^3

A 0.465 g sample of an unknown compound occupies 245 mL at 298 K and 1.22 atm. What is the molar mass of the unknown compound?

38.0 g/mol

Identify the number of bonding pairs and lone pairs of electrons in carbon dioxide.

4 bonding pairs and 4 lone pairs

What pressure will 14.0 g of CO exert in a 3.5 L container at 75°C?

4.1 atm

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: 2 NaN3 (s) → 2 Na (s) + 3 N2 (g)How many moles of N2 are produced by the decomposition of 2.88 mol of sodium azide?

4.32 mol

What volume of benzene (C6H6, d= 0.88 g/mL, molar mass = 78.11 g/mol) is required to produce of heat according to the following reaction? 2 C6H6(l) + 15 O2(g) → 12 CO2(g) + 6 H2O(g)ΔH°rxn = -6278 kJ

42 mL

A large balloon is initially filled to a volume of 25.0 L at 353 K and a pressure of 2575 mm Hg. What volume of gas will the balloon contain at 1.35 atm and 253 K?

45.0 L

What is the Celsius temperature of 100.0 g of chlorine gas in a 35.0-L container at 800 mm Hg?

46 degree celcius

Calculate the wavelength (in nm) of the blue light emitted by a mercury lamp with a frequency of 6.32 × 1014 Hz.

475 nm

The atomic number for cadmium is ________.

48

For a hydrogen atom, which electronic transition would result in the emission of a photon with the highest energy?

5p → 3s

Which of the following has the greatest mass?

6.02 × 1023 molecules of O2

Determine the mass of an object that has a volume of 88.6 mL and a density of 7.77 g/mL.

688 g

Dinitrogen monoxide gas decomposes to form nitrogen gas and oxygen gas. How many grams of oxygen are formed when 20.0 g of dinitrogen monoxide decomposes?

7.27g

Determine the shortest frequency of light required to remove an electron from a sample of Ti metal if the binding energy of titanium is 3.14 × 103 kJ/mol.

7.87 × 1015 Hz

Draw the Lewis structure for the molecule CH2CHCH3. How many sigma and pi bonds does it contain?

8 sigma, 1 pi

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide (40.31 g/mol): 2 Mg (s) + O2 (g) → 2 MgO (s)When 5.00 g of magnesium burns, the theoretical yield of magnesium oxide is ________ g.

8.29

Carbonic acid can form water and carbon dioxide upon heating. How much carbon dioxide is formed from 12.4 g of carbonic acid (62.03 g/mol)? H2CO3 → H2O + CO2

8.80g

Round off 902506 to four significant figures.

9.025 × 10^5

Lithium and nitrogen react in a combination reaction to produce lithium nitride (34.83 g/mol): 6 Li (s) + N2 (g) → 2 Li3N (s)In a particular experiment, 5.50-g samples of each reagent are reacted. The theoretical yield of lithium nitride is ________ g.

9.20

The formula of ammonium carbonate is ________.

(NH4)2CO 3

Determine the concentration of a solution prepared by diluting 20.0 mL of a 0.200 M CsOH to 250.0 mL.

0.0160 M

How many moles are there in 3.50 g of ethanol, CH3CH2OH?

0.0761 mol

What mass (in kg) does 4.41 moles of copper have?

0.280 kg

Which of the following solutions will have the highest concentration of chloride ions?

0.60 M AlCl3

How many of the following species are paramagnetic?

1

Consider the molecule below. Determine the hybridization at each of the 3 labeled atoms.

1 = sp 2, 2 = sp 3, 3 = sp 3

Consider the molecule below. Determine the molecular geometry at each of the 3 labeled atoms.

1 = trigonal planar, 2 = tetrahedral, 3 = trigonal pyramidal

Predict the charge of the most stable ion of cesium.

1+

How many moles of RbI are required to make 350 mL of a 3.00 M solution?

1.050 moles

A mixture of 10.0 g of Ne and 10.0 g Ar have a total pressure of 1.6 atm. What is the partial pressure of Ne?

1.1 atm

Using the following thermochemical equation, determine the amount of heat produced per kg of CO2 formed during the combustion of benzene (C6H6). 2 C6H6(l) + 15 O2(g) → 12 CO2(g) + 6 H2O(g)ΔH°rxn = -6278 kJ

1.19 × 10 4 kJ/kg CO2

When 12.0 g of calcium metal is reacted with water, 5.00 g of calcium hydroxide (74.10 g/mol) is produced. Using the following balanced equation, calculate the percent yield for the reaction. Ca (s) + 2 H2O (l) → Ca(OH)2 (aq) + H2 (g)

22.5%

Calculate the molar mass for Ca(ClO4)2.

238.98 g/mol

Determine the theoretical yield and the percent yield if 21.8 g of K2CO3 is produced from reacting 27.9 g KO2 with 29.0 L of CO2 (at STP). The molar mass of KO2 = 71.10 g/mol and K2CO3 = 138.21 g/mol. 4 KO2 (s) + 2 CO2 (g) → 2 K2CO3 (s) + 3 O2 (g)

27.1 g, 80.4% yield

Determine the volume of H2S (at 375 K and 1.20 atm) needed to produce 55.0 g of S. Assume that there is excess SO2 present. 2 H2S (g) + SO2 (g) → 3 S (s) + 2 H2O (g)

29.3 L

Determine the final temperature of a gold nugget (mass = 376 g) that starts at 398 K and loses 4.85 kJ of heat to a snowbank when it is lost. The specific heat capacity of gold is 0.128 J/g°C.

297 K

How many unpaired electrons are present in the ground state P atom?

3

Which atom in each group (I and II) has the smallest atomic radius? (I) Ca, Ti, Br(II) O, S, Se

Br;O

Define a greenhouse gas.

Greenhouse gases allow visible light to pass through and warm the Earth's surface, and prevent heat energy from radiating back out into space.

Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of H2SO4 and KOH are mixed.

H+ (aq) + OH- (aq) → H2O (l)

Place the following in order of increasing B-A-B bond angle, where A represents the central atom and B represents the outer atoms in each molecule. HCNH2OH3O+

H2O < H3O+ < HCN

Which compound has the shortest carbon-carbon bond length?

HCCH

A student performs an experiment to determine the density of a sugar solution. She obtains the following results: 1.80 g/mL, 1.79 g/mL, 1.80 g/mL, 1.79 g/mL. If the actual value for the density of the sugar solution is 1.79 g/mL, which statement below best describes her results?

Her results are both precise and accurate

Which of the following statements is FALSE?

It is not possible for two atoms to share more than two electrons.

Which reaction below represents the electron affinity of K?

K (g) + e- → K- (g)

Identify the cation.

K+

Give the spectator ions for the reaction that occurs when aqueous solutions of K2S and Fe(NO3)2 are mixed.

K+ and NO3-

List the following compounds in decreasing electronegativity difference.

KF > HCl > Br2

Determine the limiting reactant (LR) and the mass (in g) of nitrogen that can be formed from 50.0 g N2O4 and 45.0 g N2H4. Some possibly useful molar masses are as follows: N2O4 = 92.02 g/mol, N2H4 = 32.05 g/mol. N2O4 (l) + 2 N2H4 (l) → 3 N2 (g) + 4 H2O (g)

LR = N2O4, 45.7 g N2 formed

Place the following in order of decreasing magnitude of lattice energy.

Li2O > K2O > Rb2S

Choose the reaction that illustrates ΔH°f for Mg(NO2)2.

Mg (s) + N2 (g) + 2 O2 (g) → Mg(NO2)2 (s)

Place the following in order of increasing bond length. NO2- NO3- NO

NO < NO2- < NO3-

Place the following in order of increasing metallic character. RbCsKNa

Na < K < Rb

Which of the following elements is NOT a metal?

Ne

Which element has the most negative electron affinity?

O

In which of the following sets do all species have the same number of protons?

O, O2-, O2+

sing Lewis structures and formal charge, which of the following ions is most stable,? OCN- ONC- NOC-

OCN-

Which of the following resonance structures for OCN- will contribute most to the correct structure of OCN- ?

O—C≡N, with three lone pairs on O and one lone pair on N

Which of the following elements is a transition metal?

Ru

What period 3 element has the following ionization energies (all in kJ/mol)? IE1 = 1000IE2 = 2250IE3 = 3360IE4 = 4560IE5 = 7010IE6 = 8500IE7 = 27,100

S

In which set do all elements tend to form anions in binary ionic compounds?

Se, F, Cl

Draw the Lewis structure for NO3- including any valid resonance structures. Describe the resonance hybrid of the nitrate ion.

The nitrate ion contains three N—O bonds that are equivalent to 1 1/3 bonds.

Which of the following is TRUE if ΔEsys = - 100 J?

The system is losing 100 J, while the surroundings are gaining 100 J.

Which of the following occurs as the energy of a photon increases?

The wavelength gets shorter.

What element is undergoing oxidation (if any) in the following reaction? Zn (s) + 2 AgNO3 (aq) → Zn(NO3)2 (aq) + 2 Ag (s)

Zn

Which ion does NOT have a noble gas configuration in its ground state?

Zn2+

Give the ground state electron configuration for Sn.

[Kr]5s24d105p2

For a particular element, identify the species that has the largest radius.

anion

Of the following, which element has the highest first ionization energy?

bromine

Which of the following elements is a solid at room temperature?

calcium

dentify the element that bromine forms a covalent bond with.

carbon

Give the name for HNO3.

nitric acid

Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of Al(C2H3O2)3 and LiNO3 are mixed.

no reaction occurs

Which one of the following elements is a poor conductor of heat and electricity?

phosphorus

Identify the charges of the protons, neutrons, and electrons.

protons +1, neutrons 0, electrons -1

Which of the following signs on q and w represent the surroundings that is doing work on the system, as well as losing heat to the surroundings?

q = -, w = +

What are the possible orbitals for n = 4?

s,p,d,f

Describe a pi bond.

side by side overlap of p orbitals

Which of the following elements has chemical properties similar to tellurium?

sulfur

Determine the electron geometry (eg), molecular geometry (mg), and polarity of PCl3.

tetrahedral, mg = trigonal pyramidal, polar

Define specific heat capacity.

the quantity of heat required to raise the temperature of 1 gram of a substance by 1°C

Match: Match the following. Some questions may have more than one answer, but you need to pick the best one. Answers may only be used once. (SF4-see-saw molecular geometry) (XeCl4-square planar molecular geometry) (CH2F2-polar) (BCl3- nonpolar, but contains at least one polar covalent bond) (sp- linear electron domain geometry) (sp2- trigonal planar electron domain geometry) (sp3- tetrahedral electron domain geometry) (sp3d- trigonal bipyramidal electron domain geometry) (sp3d2- octahedral electron domain geometry) (BeF2- sp hybridized central atom)

(SF4-see-saw molecular geometry) (XeCl4-square planar molecular geometry) (CH2F2-polar) (BCl3- nonpolar, but contains at least one polar covalent bond) (sp- linear electron domain geometry) (sp2- trigonal planar electron domain geometry) (sp3- tetrahedral electron domain geometry) (sp3d- trigonal bipyramidal electron domain geometry) (sp3d2- octahedral electron domain geometry) (BeF2- sp hybridized central atom)

Match the following. (Sr-Sr D. metallic bond) (Cs-I B. weakest ionic bond) (Ca-O C. highest melting point) (Se-I E. longest covalent bond) (C=N A. strongest covalent bond)

(Sr-Sr D. metallic bond) (Cs-I B. weakest ionic bond) (Ca-O C. highest melting point) (Se-I E. longest covalent bond) (C=N A. strongest covalent bond)

Match: (Valence electrons-electrons in the outermost shell) (core electrons-electrons in completed shells) (number of unpaired electrons in Na-1) (0-number of unpaired electrons in Zn2+) (number of unpaired electrons in Zn2+-2)

(Valence electrons-electrons in the outermost shell) (core electrons-electrons in completed shells) (number of unpaired electrons in Na-1) (0-number of unpaired electrons in Zn2+) (number of unpaired electrons in Zn2+-2)

Choose the orbital diagram that represents the ground state of N.

(up,down)(up,down)(up,up,up)

Draw the best Lewis structure for the free radical, NO2. What is the formal charge on the N?

+1

Determine the oxidation state of P in PO33-.

+3

Given w = 0, an endothermic reaction has the following.

+ΔH and +ΔE

Choose the best Lewis structure for BeF2.

-->

A 35.6 g sample of ethanol (C2H5OH) is burned in a bomb calorimeter, according to the following reaction. If the temperature rose from 35.0 to 76.0°C and the heat capacity of the calorimeter is 23.3 kJ/°C, what is the value of ΔH°rxn? The molar mass of ethanol is 46.07 g/mol. C2H5OH(l) + 3 O2(g) → 2 CO2(g) + 3 H2O(g)ΔH°rxn = ?

-1.24 × 10 3 kJ/mol

se the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction: 2 NO(g) + O2(g) → 2 NO2(g)ΔH°rxn = ? Given: N2(g) + O2(g) → 2 NO(g)ΔH°rxn = +183 kJ 1/2 N2(g) + O2(g) → NO2(g)ΔH°rxn = +33 kJ

-117 kJ

Calculate the energy change associated with the transition from in the hydrogen atom.

-2.04 × 10-18 J

Calculate the change in internal energy (ΔE) for a system that is giving off 25.0 kJ of heat and is changing from 12.00 L to 6.00 L in volume at 1.50 atm pressure. (Remember that 101.3 J = 1 L ∙atm)

-24.1 kJ

Use the bond energies provided to estimate ΔH° rxn for the reaction below. CH3OH (l) + 2 O2 (g) → CO2 (g) + 2 H2O (g)ΔH°rxn = ? BondBond Energy (kJ/mol) C-H414 C-O360 C=O799 O=O 498 O-H464

-392 kJ

Use the ΔH°f and ΔH°rxn information provided to calculate ΔH°f for SO3 (g): ΔH°f (kJ/mol)2 SO2(g) + O2(g) → 2 SO3(g)ΔH°rxn = -198 kJ SO2(g)-297

-396 kJ/mol

Choose the best Lewis structure for SF4.

->

Choose the best Lewis structure for SO42- .

->

Calcium oxide (56.08 g/mol) reacts with water in a combination reaction to produce calcium hydroxide (74.10 g/mol): CaO (s) + H2O (l) → Ca(OH)2 (s)A 2.00-g sample of CaO is reacted with 1.93 g of H2O. How many grams of excess reactant remain after the reaction is complete?

1.29

Determine the molarity of a solution formed by dissolving 97.7 g LiBr in enough water to yield 750.0 mL of solution.

1.50 M

A gas mixture contains Rn, He and N2. What is the total pressure of the mixture, if the mole fraction of N2 is 0.350 and the partial pressure of N2 is 0.580 atm?

1.66 atm

According to the following reaction, how many moles of Fe(OH)2 (89.87 g/mol) can form from 175.0 mL of 0.227 M LiOH (23.95 g/mol) solution? Assume that there is excess FeCl2 (126.75 g/mol). FeCl2 (aq) + 2 LiOH (aq) → Fe(OH)2 (s) + 2 LiCl (aq)

1.99 × 10-2 moles

Which of the following contains the most atoms? You shouldn't need to do a calculation here.

10.0 g Li

Which of the following substances (with specific heat capacity provided) would show the greatest temperature change upon absorbing 100.0 J of heat?

10.0 g Pb, CPb = 0.160 J/g°C

Silver has an atomic mass of 107.868 amu. The Ag-109 isotope (108.905 amu) is 48.16%. What is the amu of the other isotope?

106.9 amu

Give the approximate bond angle for a molecule with a tetrahedral shape.

109.5 degrees

How many moles of potassium are contained in 449 g of potassium?

11.5 moles

If the percent yield for the following reaction is 65.0%, how many grams of KClO3 (122.55 g/mol) are needed to produce 32.0 g of O 2? 2 KClO3 (s) → 2 KCl (s) + 3 O2 (g)

126 g

hich of the following volumes is equal to 16 mL?

16 cm3

An atom of 32P contains ________ neutrons.

17

Give the number of electrons in P3-.

18

Aluminum metal reacts with aqueous iron(II) chloride to form aqueous aluminum chloride and iron metal. What is the stoichiometric coefficient for aluminum when the chemical equation is balanced using the lowest, whole-number stoichiometric coefficients?

2

How many of the following molecules are polar? BrF3CS2SF4SO3

2

Give the complete ionic equation for the reaction (if any) that occurs when aqueous solutions of K2S and Fe(NO3)2 are mixed.

2 K+ (aq) + S2- (aq) + Fe2+ (aq) + 2 NO3- (aq) → FeS(s) + 2 K+ (aq) + 2 NO3- (aq)

What is the mass of 8.00 × 1022 molecules of NH3?

2.26g

sing the graph below, determine the gas that has the lowest density at STP.

A (the lowest curve)

Determine the oxidizing agent in the following reaction. Ni (s) + 2 AgClO4 (aq) → Ni(ClO4)2 (aq) + 2 Ag (s)

AgClO4

Write a balanced equation to show the reaction of aqueous aluminum acetate with aqueous ammonium phosphate to form solid aluminum phosphate and aqueous ammonium acetate.

Al(C2H3O2)3 (aq) + (NH4)3PO4 (aq) → AlPO4 (s) + 3 NH4C2H3O2 (aq)

Give the correct formula for aluminum sulfate.

Al2(SO4)3

dentify the species reduced. 2 Al3+ (aq) + 2 Fe (s) → 2 Al (s) + 3 Fe2+ (aq)

Al3+

Which of the following statements is TRUE? Part of the Bohr model proposed that electrons in the hydrogen atom are located in "stationary states" or particular orbits around the nucleus. An orbital is the volume in which we are most likely to find an electron. The emission spectrum of a particular element is always the same and can be used to identify the element. The uncertainty principle states that we can never know both the exact location and speed of an electron. All of the statements are true.

All of the statements are true.

Which of the following statements is TRUE?

An ionic bond is much stronger than most covalent bonds.

Which of the compounds C4H10, CaCl2, Cu(NO3)2, PCl3 are expected to exist as molecules?

C 4H10 and PCl3

What is the empirical formula for C16H32O8?

C2H4O

A certain alcohol contains only three elements, carbon, hydrogen, and oxygen. Combustion of a 40.00 gram sample of the alcohol produced 76.40 grams of CO2 and 46.96 grams of H2O. What is the empirical formula of the alcohol?

C2H6O

Choose the reaction that represents the combustion of C6H12O2.

C6H12O2 (l) + 8 O2 (g) → 6 CO2 (g) + 6 H2O (g)

Choose the compound below that contains at least one polar covalent bond, but is nonpolar.

CCl4

What is the empirical formula of a substance that contains 2.64 g of C, 0.444 g of H, and 3.52 g of O?

CH2O

Place the following in order of increasing radius. Ca2+ S2- Cl-

Ca2+ < Cl- < S2-

Which of the following species will have the highest ionization energy?

Cs+

Determine the name for N2O5.

dinitrogen pentoxide

How many significant figures are there in the answer to the following problem?

four

Give the definition for effusion.

gas molecules escape from a container into a vacuum through a small hole

Identify a characteristic that is NOT true of halogens.

halogens are metalloids

Write the name for FeS

iron(II) sulfide

Determine the electron geometry (eg), molecular geometry (mg), and polarity of N2O (N central).

linear, mg = linear, polar

Identify the correct values for a 3p orbital.

n = 3, l = 1, ml = 0

Give the set of four quantum numbers that could represent the last electron added (using the Aufbau principle) to the Br atom. Selected Answer:

n = 4, l = 1, ml = 1, ms = +1/2

Each of the following sets of quantum numbers is supposed to specify an orbital. Choose the one set of quantum numbers that does NOT contain an error.

n = 4, l = 3, ml = -1