chemistry unit exam

Which subatomic particle determines the element's identity?

Proton

Which set represents isotopes?

^35Cl and ^37Cl

How is the first ionization energy trend across period 3 best described?

Generally increasing with dips at Al and S

Which orbital can hold a maximum of 10 electrons?

d

What is the number of valence electrons in a ground state phosphorus atom?

5

Which technique provides evidence for electronic configuration by measuring ionization energies?

Photoelectron spectroscopy (PES)

Which statement about effective nuclear charge (Z_eff) is true?

Z_eff increases across a period

What do the peak positions in a PES spectrum correspond to?

Electron binding energies of subshells

Which element has the largest atomic radius?

Na

Removing which electron requires the greatest energy in Mg?

Third (from 2p)

How is the bonding in NaCl best described?

Ionic with lattice of cations and anions

Which molecule has trigonal planar geometry?

SO3

What is the hybridization of carbon in ethene (C2H4)?

sp^2

Which compound has the strongest lattice energy?

LiF

Which statement is true about resonance?

Resonance shows delocalization with equivalent contributing structures

In a metallic solid, what arises from electrical conductivity?

Delocalized electron sea

Which molecule exhibits hydrogen bonding?

HF

Which statement about network covalent solids is correct?

Very hard with directional covalent bonds

Which ion is most likely to be octahedrally coordinated in a crystal?

Al3+

In VSEPR, how do lone pairs on the central atom generally affect bond angles?

Decrease bond angles

What is the predominant intermolecular force in CO2(l)?

London dispersion

A liquid with strong IMFs typically has what property?

High boiling point

Which element has the highest boiling point?

Xe

Which solution property is colligative?

Boiling point elevation

What does the region above both curves in a simplified phase diagram correspond to?

Gas

Increasing the surface area of a liquid generally does what?

Increases evaporation rate

Which aqueous solution would have the highest freezing point depression?

0.5 m CaCl2

What does Raoult's law state for ideal solutions?

Pcomponent = Xcomponent * P^0_component

As temperature increases, how does the solubility of gases in water change?

Decreases

What does chromatography primarily separate components based on?

Differences in intermolecular interactions/affinity

Balance the equation: ___Al + ___O2 → ___Al2O3.

4, 3, 2

Which species is oxidized in the reaction: 2Fe + 3Cl2 → 2FeCl3?

Fe

Which is a strong electrolyte?

Na2SO4(aq)

What is the limiting reactant when 2.0 mol H2 reacts with 1.0 mol O2 to form H2O?

O2

What occurs when mixing 0.10 M AgNO3 with 0.10 M NaCl?

AgCl(s)

What is the net ionic equation for strong acid-strong base neutralization?

H+ + OH- → H2O

Which species is amphiprotic?

HSO4-

From the combustion of propane: C3H8 + 5O2 → 3CO2 + 4H2O, how many moles of CO2 are produced from 2.0 mol C3H8?

6.0

Which observation indicates a chemical reaction?

Temperature change upon mixing

Which species acts as a spectator ion in the precipitation of BaSO4?

Na+

What are the units of k in the rate law: rate = k[A]^2[B] when rate is in M/s?

M^-2 s^-1

For a first-order reaction, what does a plot of ln[A] vs. time yield?

Straight line with slope -k

How do catalysts increase reaction rate?

Lowering activation energy

In a zero-order reaction, what happens when [A] is doubled?

No change

What does the method of initial rates primarily determine?

Order with respect to reactants

For the elementary step A + B → C, what is the molecularity?

Bimolecular

What does collision theory require for a reaction?

Correct orientation and sufficient energy

Which integrated rate law fits a second-order reaction in A?

1/[A] = kt + 1/[A]_0

What does the Arrhenius equation relate k to?

Temperature and activation energy

Where is the activated complex located on a reaction energy diagram?

Peak of the curve