General Chemistry I EXAM 2

Ammonium

+1 Charge

Mercury (I)

+1 Charge

The shape of a sp3d2 hybrid orbital is tetrahedral , with a bond angle(s) of 109.5° .

-octahedral -90°

What would be the bond order for the diatomic molecule shown below?

1

For the above molecule: The number if sigma bonds is __________ , and the number of pi bonds is __________.

11 3

Write an electron configuration for the following ions: Full electron configuration for the nitrogen atom

1s22s22p3

Write an electron configuration for the following ions: Full electron configuration for the nitrogen ion

1s22s22p6

What would be the bond order for the diatomic molecule shown below?

2

Elements in group 16 will tend to form ion with a charge of ____.

2-

State the number of valence electrons in: Gallium

3

How many electrons are shared in a double covalent bond?

4

State the number of valence electrons in: Tin

4

Write an electron configuration for the following: How many valence electrons does Zr have?

4

State the number of valence electrons in: Group 15

5

State the number of valence electrons in: Group 17

7

State the number of valence electrons in: {Kr}5s24d7

9

State the number of valence electrons in: {Xe}6s24f7

9

An element's electronic configuration ends in s1. Which group does it belong to?

Alkali Metals

Write the symbol of an inner transition metal that you would expect to follow Hund's rule

All possible answers: Yb or No or Eu or Am

Hypervalent molecules

Also known as expanded octet is a molecule that contains one or more main group elements apparently bearing more than eight electrons in their valence shells. Phosphorus pentachloride (PCl5), sulfur hexafluoride (SF6), chlorine trifluoride (ClF3), the chlorite (ClO−2) ion, and the triiodide (I−3) ion are examples of hypervalent molecules.

Draw the Lewis Dot Structure for the ion, NX4+, if X is in group 17 What is the electron pair geometry of this compound? What is the molecular geometry of this compound? What are the bond angles in the molecular geometry of this compound? N-X is a polar bond. Is the NX4+ molecule polar? yes

Answer 1:tetrahedral Answer 2:tetrahedral Answer 3:109.5° Answer 4:no

molecule A is PF5. Is the molecule polar? yes molecule B is SeF4. Is the molecule polar? molecule C is BrF3. Is the molecule polar? molecule D is IBr2- . Is the molecule polar? if molecule D is IF2- . Is the molecule polar?

Answer 1:yes Answer 2:yes Answer 3:yes Answer 4:no Answer 5:no

A. The bonds labeled A are pi bonds resulting from the_______________(1)overlap of________(2)_. B. The bond labeled B is a___________(3)bond resulting from the_____________(4)overlap of a hybridized s orbital and a hybridized sp2 orbital

Answer 1a:sigma Answer 2a:head on (end-to-end) Answer 3a: an unhybridized s orbital and a hybridized sp2 orbital Answer 4b:sigma Answer 5b:head on (end-to-end) Answer 6b:two hybridized sp2 orbitals

Which of the following has an incomplete octet in its Lewis structure? -CO2 -SO2 -Cl2 -BCl3

BCl3

An element has an ionization energy of 780kJ/mol. Based on general trends, the element _______________ and the element on the _______________are likely to have a lower ionization energies.

Below Left

Ionic bonds

Bonds between a metal and a nonmetal

Meatllic Bond

Bonds between two metals

Which of the following elements can NOT form hypervalent molecules? (select all that apply) -Iodine -Boron -Phosphorus -Sulfur -Arsenic -Oxygen -Flourine

Boron Oxygen Flourine

Consider the following electron configurations: Element A: 1s2 2s1 Element B: 1s2 2s2 2p6 3s1 Element C: 1s2 2s2 2p6 3s2 3p6 4s1 Which of the following is the correct order for increasing IE1 (i.e. smallest to largest)

C < B < A

The bond angles in CH4, NH3, and H2O are 109.5°, 107°, and 104.5°, respectfully. Which of the statements best describes the variance in bond angles?

CH4 has no lone pairs of electrons on the central atom so the optimal molecular shape would be tetrahedral with bond angles of 109.5°. In NH3 and H2O there are 1 and 2 lone pairs, respectfully, so more repulsion exists between the bonds and lone pairs, as a result, the bond angles are less than 109.5°.

Ionic vs Covalent

Covalent or molecular compounds form when elements share electrons in a covalent bond to form molecules. Molecular compounds are electrically neutral. Ionic compounds are (usually) formed when a metal reacts with a nonmetal (or a polyatomic ion) and has a partial charge

Which diatomic, homonuclear compound does the molecular orbital diagram below represent (atomic orbital electrons have been left blank intentionally, you can fill them in if it helps you)?

F2

True or False? All polyatomic ions are anions.

False

True or false? The F- and Li+ ions are isoelectronic.

False

Based on the sequential ionization energies pattern provided for element X, what is the most likely group in which element X resides? IE1: 480 kJ/mol IE2: 720 kJ/mol IE3: 1,500 kJ/mol IE4: 14,800 kJ/mol IE5: 18,000 kJ/mol IE6: 19,300 kJ/mol

Group 13

Which polyatomic ion represents dihydrogen phosphite?

H2PO3-

Which polyatomic ion represents hydrogen phosphate?

HPO42-

An element's electronic configuration ends in p5. Which group does it belong to?

Halogens

Which statement is false?

Hybrid orbitals exist in isolated atoms.

Which of the following is the least polar? -IF -IBr -MgBr -HF

IBr

Which of the following is the most polar? -IBr -IF -HF -MgBr

IF

Polarity

In chemistry, polarity refers to the way in which atoms bond with each other. When atoms come together in chemical bonding, they share electrons. A polar molecule arises when one of the atoms exerts a stronger attractive force on the electrons in the bond.

What type of neutral atom does the orbital diagram below represent? Type in the symbol of the element.

Iron (Fe)

Ion vs Isotope

Isotopes are atoms that have the same numbers of protons but different numbers of neutrons. An ion is an atom that has gained or lost electrons, so it now has more or fewer electrons than it does protons. So an ion has a negative or positive charge.

A compound is made by combining a metal ion (M3+) with a nitrate anion. What is the formula for the compound?

M(NO3)3

A compound is made by combining a metal ion (M+) with a carbonate anion. What is the formula for the compound?

M2CO3

A binary compound is made by combining the following two ions. What is the formula for the compound? Q3+ and X2-

Q2X3

A binary compound is made by combining the following two ions. What is the formula for the compound? Q2+ and X3-

Q3X2

When drawing Lewis Structures, after drawing the skeletal structure and distributing all the electrons around the external atoms, what action should be taken if the central atom does not have a completed octet?

Rearrange lone pair(s) from an external atom to form a multiple bond to the central atom.

Which is expected to have the largest radius, S, Cl, Se, Br?

Se

What type of neutral atom does the orbital diagram below represent? Type in the symbol of the element.

Sodium (Na)

The Octet Rule

States that atoms must attain 8 electrons in outermost energy level to become stable. Subatomic Particles. Particles SMALLER than an atom.

What is the molecular geometry

T shaped

Which statement(s) below holds true for describing the polarity of the PO bond? Select all that apply.

The O has a partial negative charge.

Select the correct answer below:

The two dashed lines indicate the formation of one pi-bond that is formed from the two unhybridized p orbitals.

Electron geometry vs Molecular Geometry

They differ as molecular geometry refers to the arrangement of atoms in a molecule around the central atom(s), while electron geometry refers to the arrangement of electron density around the central atom(s). Molecular and electron geometry can be the same when there are no lone pairs around the central atom in a molecule, the electron and molecular geometry are the same.

Whats is the electron geometry

Trigonal Bipyramidal

A compounds is made up from the combination of two elements, Q and X. If both Q and X are nonmetallic, the compound is likely to be molecular in nature.

True

A compounds is made up from the combination of two elements, Q and X. If the compound conducts electricity when dissolved in water, the compound is likely to be ionic in nature.

True

True or false? The N- and F+ ions are isoelectronic.

True

Degenrate Orbitals

When each orbital has the same energy

Write an electron configuration for the following ions: Using noble gas notation for Cr2+

[Ar]3d4

Write an electron configuration for the following: Write the noble gas (abbreviated) configuration for Ag

[Kr]5s14d10

Write an electron configuration for the following ions: Using noble gas notation for the Molybdenum atom, Mo

[Kr]5s24d4

Write an electron configuration for the following: Write the noble gas (abbreviated) configuration for Bk

[Rn]7s25f8 or [Rn]7s25f9

Octet

a group of eight people or things.

Ionic compounds typically form between _____.

a metal and a nonmetal

Paramagnetic

a substance or element with unpaired electrons -weekly attracted to an external magnetic field

Diamagnetic

an element composed of only paired electrons

When in-phase atomic orbitals combine, they create

bonding molecular orbitals

Covalent bonds

bonds between a metal and a metal

Which is expected to have the smallest radius, Ba2+, Ba, Ca2+, Ca?

calcium ion

Type the name of the polyatomic ion represented by CrO42-

chromate

If the electron affinity for an element is positive, this means that

energy is absorbed when an atom gains an electron (unfavorable)

Isoelectronic

having the same numbers of electrons or the same electronic structure

Which is expected to have the largest radius, Ba2+, I-, Xe, Cs+? You Answered

iodine ion

What type of compund is AlSi

ionic

Type the name of the polyatomic ion represented by NO2-

nitrite

Draw the Lewis Dot Structure for the ion, XCl5, if X is in group 17 and is considerable less polar than Cl. What is the electron pair geometry of this compound?

octahedral octahedral is best described as a central atom symmetrically arranged by six other atoms

The water molecule has an overall dipole with the negative portion

pointing toward the oxygen atom

What type of compound is Nitrogen and Oxygen

polar covalent

Polar vs nonpolar

polar is unequal sharing of electrons nonpolar is equal sharing of electrons

When two or more equivalent Lewis structures can be written for a given molecule it is said to have _______structures.

resonance

Double and triple bonds form because

single covalent bonds do not give all of the atoms in the molecule eight valence electrons

Which hybrid orbital does the diagram above represent? sp3 Which atom could this be? C

sp

What is the hybridization of the C labeled D?

sp2

What is the hybridization of the C labeled E?

sp2

What is the hybridization of the C labeled C?

sp3

Which hybrid orbital does the diagram above represent? sp Which atom could this be? C

sp3

The hybridization of the S in the above molecule is

sp3d

The hybridization of the Xe in the above molecule is

sp3d2

What is the molecular geometry of this compound? t-shaped What are the bond angles in the molecular geometry of this compound? Is the molecule polar?

square pyramidal 90 and 180 degrees Yes (it is polar)

Is it true that a molecule with polar bonds will always be polar?

that is false, molecular polarity is determined by molecular shape

The shape of a sp3d hybrid orbital is tetrahedral , with a bond angle(s) of 109.5° .

trigonal bipyramidal 90° and 120°