Chemistry Review: Exam 2

The number of 4p electrons in As.

3

Arrange the following elements in order of decreasing first ionization energy: Po, Cl, Te, and Se.

Laregest) Cl Se Te Po (smallest

What is the formula for the compound nitrogen monoxid What is the formula for the compound methane?

NO CH4..... (small subscripts)

Enter the condensed electron configuration for the following three ions: Co2+ N3− Ca2+ Express your answers in condensed form separated by commas.

[Ar]3d^7, [He]2s^22p^6, [Ar]

What type of bonding occurs in iron(III) chloride, FeCl3? covalent metallic ionic

ionic

Give the systematic name for the compound Fe2(SO4)3.

iron(III) sulphate

Write the electron configuration for Zn2+? Express your answer in condensed form

ANSWER: [Ar]3d^10

Use the periodic table to determine the electron configuration for iodine (I). Express your answer in condensed form.

[Kr]5s^24d^105p^5

Prefix Number mono.....one di............two tri...........three tetra.......four penta.......five hexa........six hepta........seven octa ...........eight nona.......nine deca.......... ten

yep

Write the correct electron configuration for S. Express your answer in complete form,

1s^22s^22p^63s^23p^4

The number of 2s electrons in Be.

2

The number of 3d electrons in V.

3

How many orbitals are present when l=3? 1 3 5 7 9

7

The number of 3d electrons in Co.

7

Enter the formula for the compound barium oxide.

BaO

How many 8p orbitals exist? ANSWER: 3 1 0 8 5

3

Give each ionic compound an appropriate name. Part A SnI4 Spell out the full name of the compound. Part B CrS Spell out the full name of the compound. Part C RbI Spell out the full name of the compound. Part D BaBr2 Spell out the full name of the compound.

ANSWER: tin(IV) iodide ANSWER: chromium(II) sulfide ANSWER: rubidium iodide ANSWER: barium bromide

On the basis of periodic trends, determine the element in each pair with the higher first ionization energy (if possible). Sn or I ANSWER: a.Sn b.I c.It is impossible to determine based on periodic trends alone. Part B Ca or Sr ANSWER: a.Ca b.Sr c.It is impossible to determine based on periodic trends alone. Part C C or P ANSWER: a.C b.P c.It is impossible to determine based on periodic trends alone. Part D F or S ANSWER: a.F b.S c.It is impossible to determine based on periodic trends alone.

B A C A

Both of the sulfur-chlorine single bonds in SCl2..... (small subscripts) are polar. In which direction should the polarity arrows point? ANSWER: a. to the right b. to the left c. toward the central sulfur atom d. away from the central sulfur atom hint: The negative pole of a polar bond is always the more electronegative element.

D

Arrange the following atoms according to decreasing effective nuclear charge experienced by their valence electrons: S, Na, Al, and Si.

Largest) S Si Al NA (Smallest

Elements with 3 or fewer valence electrons tend to lose electrons, and elements with 5 or more valence electrons tend to gain electrons.

Thus, Ga and Pb tend to lose electrons, whereas Cl and Se tend to gain electrons.

Write the electron configuration for V3+

[Ar] 3d^2

Write the electron configuration for Mo3+

[Kr]4d^3 of 1s^22s^22p^63s^23p^64s^23d^104p^65s^04d^3.

identify the energy change that occurs when an electron is added to a neutral gaseous O atom, forming an O− ion: O(g)+e−→O−(g) ANSWER: a. −710 kJ b. +142 kJ c. −142 kJ d. +710 kJ

c

Group Tendency Charge 1A... Lose one electron... +1 2A... Lose two electrons +2 3A Lose three electrons +3 5A Gain three electrons -3 6A Gain two electrons -2 7A Gain one electron -1 8A Rarely gain or lose electrons 0

yep

[Kr]5s24d105p2 Express your answer as a chemical symbol.

ANSWER: Sn

The shell number is equal to the n value. The type of subshell corresponds to the ℓ value.

Type of subshell ℓ s..................0 p.................1 d................ 2 f..................3

Each set of quantum numbers is supposed to specify an orbital. However, each set contains one quantum number that is not allowed. Replace the quantum number that is not allowed with one that is allowed. n=3;l=3;ml=+2 a. ml=0 b. n=4 c. l=4 d. n=2

b

How is the electron configuration of a cation different? ANSWER: a. add the number of electrons required by the magnitude of the charge of the cation b. subtract the number of electrons required by the magnitude of the charge of the cation c. the electron configurations of an cation and the corresponding neutral atom are the same

b

identify the nobel gas proceeding the metal Li, lithium, is located in group 1A and in period 2 of the periodic table. Identify the preceding noble gas. ANSWER: a.helium b.neon c.argon Hint 4. Identify the noble gas succeeding a nonmetal Se, selenium, is located in group 6A in period 4 of the periodic table. Identify the next noble gas following Se in the periodic table. ANSWER: a.argon b.krypton c.xenon

A B

Hint 1. Balance the charges in an example compound How many Y2− anions are needed to balance the charge on one X+6 cation? Express your answer numerically as an integer.

ANSWER: 3

How many protons and how many inner (nonvalence) electrons does a neutral boron atom have? Express your answers as integers separated by a comma.

ANSWER: 5, 2

Determine the number of valence electrons in the neutral nonmetals How many valence electrons are in a neutral atom of As, Se, and Br, respectively? Express your answer as three integers separated by commas. Hint 2. Determine the number of valence electrons in the neutral metals How many valence electrons are in a neutral atom of K, Ca, and Ga, respectively? Express your answer as three integers separated by commas.

ANSWER: 5,6,7 ANSWER: 1,2,3

How many protons and how many inner (nonvalence) electrons does a neutral oxygen atom have? Express your answers as integers separated by a comma.

ANSWER: 8, 2

Name each of the following molecular compounds. Part A SO3..... (small subscripts) Spell out the full name of the compound. Part B SO2..... (small subscripts) Spell out the full name of the compound. Part C RnF2..... (small subscripts) Spell out the full name of the compound. Part D NO Spell out the full name of the compound.

ANSWER: sulfur trioxide Correct ANSWER: sulfur dioxide ANSWER: radon difluoride ANSWER: nitric oxide

The number of 3s electrons in Na. Express your answer as an integer.

ANSWER: 1

Determine the number of valence electrons for each of the following four elements. Ga Express your answer as an integer.

ANSWER: 3

The number of 3d electrons in Cr. Express your answer as an integer.

ANSWER: 5

As Express your answer as an ion. Rb Express your answer as an ion.

ANSWER: As3− ANSWER: Rb+

Write a formula for the compound that forms between calcium and each polyatomic ion: Part A hydroxide Express your answer as a chemical formula. Part B chromate Express your answer as a chemical formula. Part C phosphate Express your answer as a chemical formula. Part D cyanide Express your answer as a chemical formula.

ANSWER: Ca(OH)2..... (small subscripts) ANSWER: CaCrO4..... (small subscripts) ANSWER: Ca3(PO4)2..... (small subscripts) ANSWER: Ca(CN)2..... (small subscripts)

Acetic acid (C2H4O2) is the active ingredient in vinegar. Part A Calculate the mass percent composition of oxygen in acetic acid. Express your answer using four significant figures. ..... (small subscripts)

ANSWER: Mass % = 53.29%

Write a formula for the ionic compound that forms between each pair of elements. Part A magnesium and chlorine Express your answer as a chemical formula. Part B barium and oxygen Express your answer as a chemical formula. Part C strontium and sulfur Express your answer as a chemical formula. Part D beryllium and chlorine Express your answer as a chemical formula.

ANSWER: MgCl2..... (small subscripts) ANSWER: BaO..... (small subscripts) ANSWER: SrS..... (small subscripts) ANSWER: BeCl2..... (small subscripts)

Find the number of ibuprofen molecules in a tablet containing 200.0 mg of ibuprofen (C13H18O2). Express the amount to four significant figures. Part B What is the mass of a sample of water containing 3.55×1022 molecules of H2O? Express the mass in grams to three significant figures. ..... (small subscripts)

ANSWER: amount = 5.839×1020 molecules of C13H18O2 ANSWER: mass = 1.06 g

Calculate the formula mass for each of the following compounds. Part A AgCl Express your answer using two decimal places. Part B PBr3..... (small subscripts) Express your answer using two decimal places. Part C CH3CONH2..... (small subscripts) Express your answer using two decimal places. Part D Na3PO4..... (small subscripts) Express your answer using two decimal places.

ANSWER: formula mass = 143.32 amu ANSWER: formula mass = 270.67 amu ANSWER: formula mass = 59.07 amu ANSWER: formula mass = 163.94 amu

Silver chloride, often used in silver plating, contains 75.27% Ag. Part A Calculate the mass of silver chloride required to plate 225 mg of pure silver.

ANSWER: mAgCl = 299mg

Copper (II) fluoride contains 37.42% F by mass. Part A Use this percentage to calculate the mass of fluorine (in g) contained in 59.5 g of copper (II) fluoride.

ANSWER: mF = 22.3g

Name each ionic compound. Part A Mg3P2 Spell out the full name of the compound. Part B KBr Spell out the full name of the compound. Part C NaBr Spell out the full name of the compound. Part D Li2S Spell out the full name of the compound. Part E CsF Spell out the full name of the compound. Part F KI Spell out the full name of the compound.

ANSWER: magnesium phosphide ANSWER: potassium bromide ANSWER: sodium bromide ANSWER: lithium sulfide ANSWER: cesium fluoride ANSWER: potassium iodide

On the basis of periodic trends, choose the more metallic element from each pair (if possible). Part A Ge or Sn ANSWER: a. Ge b. Sn c. It is impossible to determine based on periodic trends alone. Part B Sb or Po ANSWER: a. Sb b. Po c. It is impossible to determine based on periodic trends alone. Part C Cl or I ANSWER: a. Cl b. I c. It is impossible to determine based on periodic trends alone Part D B or N ANSWER: a. B b. N c. It is impossible to determine based on periodic trends alone.

B C B A

A compound is 80.0% carbon and 20.0% hydrogen by mass. Assume you have a 100.-g sample of this compound. Part A How many grams of each element are in this sample? Enter the number of grams of carbon followed by the number of grams of hydrogen, separated by a comma (e.g., 30.0,70.0). Part B How many moles of each element are in this sample? Enter the number of moles of carbon followed by the number of moles of hydrogen, separated by a comma. Part C Based on the mole ratio you determined in Part C, what is the empirical formula of this compound? The molar mass of the compound was found to be 30.069 g/mol. What is the molecular formula?

ANSWER: mass of C, mass of H = 80.0,20.0g ANSWER: moles of C, moles of H = 6.66,19.8mol ANSWER: CH3 ..... (small subscripts) ANSWER: C2H6..... (small subscripts)

Determine the mass of oxygen in a 7.2-g sample of Al2(SO4)3. Express the mass in grams to two significant figures. Part B Butane (C4H10) is the liquid fuel in lighters. How many grams of carbon are present within a lighter containing 7.25 mL of butane? (The density of liquid butane is 0.601 g/mL.) Express the mass in grams to three significant figures. ..... (small subscripts)

ANSWER: mass of oxygen = 4.0g ANSWER: mass of carbon = 3.60g

Name each ionic compound. Part A SnBr4 Spell out the full name of the compound. Part B PbF4 Spell out the full name of the compound. Part C FeO Spell out the full name of the compound. Part D CuO Spell out the full name of the compound. Part E FeCl2 Spell out the full name of the compound. Part F NiCl2 Spell out the full name of the compound.

ANSWER: tin(IV) bromide ANSWER: lead(IV) fluoride ANSWER: iron(II) oxide ANSWER: copper(II) oxide ANSWER: iron(II) chloride ANSWER: nickel(II) chloride

The empirical formula and molar mass of several compounds are listed below. Find the molecular formula of each compound. Part A C6H7N, 186.28 g/mol Express your answer as a chemical formula. Part B C2HCl, 120.95 g/mol Express your answer as a chemical formula. Part C C5H10NS2, 593.11 g/mol Express your answer as a chemical formula. ..... (small subscripts)

ANSWER: C12H14N2..... (small subscripts) ANSWER:C4H2Cl2..... (small subscripts) ANSWER: C20H40N4S8..... (small subscripts)

Determine the empirical formula for the compound represented by each molecular formula. Part A N2O4 Express your answer as a chemical formula. Part B C5H12 Express your answer as a chemical formula. Part C C4H10 Express your answer as a chemical formula. ..... (small subscripts)

ANSWER:NO2..... (small subscripts) ANSWER:C5H12..... (small subscripts) ANSWER:C2H5..... (small subscripts)

Which set of quantum numbers cannot occur together to specify an orbital? a. n=4,l=3,ml=3 b. n=2,l=1,ml=−1 c. n=3,l=2,ml=3 d. n=3,l=2,ml=0

C

In the molecule FCl, which atom is the negative pole?

F

Of the molecules HF and HCl, which has bonds that are more polar?

HF

Enter the formula for the compound lead(II) phosphate.

Pb3(PO4)2..... (small subscripts)

Rank from largest atomic radius to smallest Ca Mg Be Sr

Sr Ca Mg Be

Write the electron configuration for O2−

[He]2s^22p^6

Use the periodic table to determine the electron configuration of bismuth (Bi). Express your answer in condensed form.

[Xe]4f^145d^106s^26p^3

For the elements with the electron affinities given in the table in the introduction, which element is most likely to accept an electron? Hint 1. How to interpret electron affinity values The values of electron affinity are given in kilojoules per mole. Negative values indicate that energy is released when an electron is added to the neutral atom. If no energy change is observed when an electron is added to the atom, then EA=0. If energy is required to add an electron to a neutral atom, the atom's electron affinity is positive. ANSWER: a. O b. As c. Mg

a

Give the ground state electron configuration for I. ANSWER: a. [Kr]5s^24d^105p^5 b. [Kr]5s^25p^6 c. [Kr]4d^105p^6 d. [Kr]5s^25d^105p^6 e. [Kr]5s^24d^105p^6

a

How is the electron configuration of an anion different from that of the corresponding neutral atom? ANSWER: a. add the number of electrons required by the magnitude of the charge of the anion b. subtract the number of electrons required by the magnitude of the charge of the anion c. the electron configurations of an anion and the corresponding neutral atom are the same

a

In an orbital diagram, the arrows are used to indicate the relative spin of an electron (indicative of its ms value). Which of the following correctly describes a violation of the Pauli exclusion principle? ANSWER: a. Arrows in the same orbital with the same direction. b. Arrows in the same subshell with the same direction. c. Arrows in the same subshell with different direction.

a

Identify the preceding noble gas for a metal Beryllium, Be, is located in group 2A and in period 2 of the periodic table. Identify the preceding noble gas. ANSWER: a.helium b.neon c.argon Identify the succeeding noble gas for a nonmetal Bromine, Br, is located in group 7A in period 4 of the periodic table. Identify the next noble gas succeeding Br in the periodic table? ANSWER: a.argon b.krypton c.xenon

a b

On the basis of periodic trends, choose the larger atom in each pair (if possible). Part A Al or S a.Al b.S c. It is impossible to determine based on periodic trends alone. Part B Ge or Po ANSWER: a.Ge b.Po c.It is impossible to determine based on periodic trends alone. Part C Cr or W ANSWER: a.Cr b.W c.It is impossible to determine based on periodic trends alone. Part D F or Se ANSWER: a.F b.Se c.It is impossible to determine based on periodic trends alone.

a c b b

What type of bonding occurs in a sample of pure copper, Cu? In other words, how is one copper atom held to another copper atom? covalent metallic ionic

metallic

Choose the element with the highest first ionization energy from each of the following pairs. Part A Kr or Br ANSWER: a. Kr b. Br Part B Na or Rb ANSWER: a. Na b. Rb Part C Rn or Pb ANSWER: a. Rn b. Pb Part D S or Sb ANSWER: a. S b. Sb

all A

If an element is located in the fourth column of the 7p block of the periodic table, which of the following would you expect to find in its electron configuration? ANSWER: a.4p^7 b.7p^4 c.s4p^7 d.p^11

b

The element that corresponds to the electron configuration 1s^22s^22p^63s^23p^64s^13d^5 is ________. a. vanadium b. chromium c. titanium d. manganese e. iron

b

identify the energy change that occurs when an electron is added to an O− ion, forming an oxide (O2−) ion: O−(g)+e−→O2−(g) ANSWER: a. −142 kJ b. +710 kJ c. +142 kJ d. −710 kJ

b

Which of the following statements is TRUE? ANSWER: a. An orbital that penetrates into the region occupied by core electrons is more shielded from nuclear charge than an orbital that does not penetrate and therefore has a lower energy. b. Two electrons in the same orbital can have the same spin. c. An orbital that penetrates into the region occupied by core electrons is less shielded from nuclear charge than an orbital that does not penetrate and therefore has a lower energy. d. It is possible for two electrons in the same atom to have identical values for all four quantum numbers. None of the above are true.

c

Part A Determine if the bond formed between I and I is pure covalent, polar covalent, or ionic. ANSWER: a. polar covalent b. ionic c. pure covalent Part B Determine if the bond formed between Cs and Br is pure covalent, polar covalent, or ionic. ANSWER: a. ionic b. pure covalent c. polar covalent Part C Determine if the bond formed between P and O is pure covalent, polar covalent, or ionic. ANSWER: a. pure covalent b. ionic c. polar covalent

c a c

What is the name for the compound CCl4? What is the name for the compound P4O10

carbon tetrachloride tetraphosphorus decoxide

According to Hund's rule, the electrons will arrange in the degenerate set of orbitals with one electron in each orbital with like spins before any pairing occurs. So for Hund's violation to occur the subshell must have a degenerate set of orbitals. In which type of subshell could a Hund's rule violation occur? ANSWER: a. s only b. p only c. d only d. p and d e. s, p, and d

d

Choose the statement that is TRUE. ANSWER: a. Core electrons are the easiest of all electrons to remove. b. Outer electrons efficiently shield one another from nuclear charge. c. Valence electrons are most difficult of all electrons to remove. d. Core electrons effectively shield outer electrons from nuclear charge. e. All of the above are true.

d

Why does an electron found in a 2s orbital have a lower energy than an electron found in a 2p orbital in multielectron systems? ANSWER: a. There are more nodes found in the 2s orbital. b. Electrons in the 2s orbital are shielded by electrons in the 2p. c. The larger number of electrons found in the 2p orbital leads to greater repulsion. d. The shape of the orbital ultimately determines the energy of the electrons. e. Electrons in the 2s orbital can penetrate the 1s orbital and be closer to the nucleus .

e

Give the systematic name for the compound NaNO3.

nitrate