MODERN STATES CHEMISTRY CLEP

Which of the following best explains why a color indicator is used in titrations?

To visually signal the endpoint of the titration

In a lab experiment, what is the independent variable?

The factor you change or control

In a simple filtration setup, what is the function of the filter paper?

To separate solids from liquids

When using a thermometer, which of the following improves accuracy?

Ensuring the bulb is fully submerged without touching the container

Which of the following is most important when recording data in a lab notebook

Record data in ink and never erase

If the temperature increases during a reaction, the process is:

Exothermic

Which species is oxidized in the reaction: Zn + Cu²⁺ → Zn²⁺ + Cu?

Zn

Which of the following is reduced in the reaction: 2Al + 3Cu²⁺ → 2Al³⁺ + 3Cu?

Cu²⁺

A higher standard reduction potential means:

The substance is more easily reduced

Which statement is true of electrons in an external circuit of a galvanic cell?

They flow from anode to cathode

Which of the following must be known to calculate the amount of metal deposited during electrolysis?

Current, time, and molar mass

What is the change in oxidation number for chlorine in the reaction: Cl₂ → Cl⁻?

0 to –1

What does a positive cell potential (E°cell > 0) indicate about a redox reaction?

It is spontaneous

In electrolysis, electrical energy is used to:

Drive nonspontaneous chemical reactions

How many moles of electrons are required to reduce 1 mole of Cu²⁺ to Cu(s)?

2

What determines whether a molecule is polar or nonpolar?

Bond polarity and molecular geometry

What does the VSEPR theory help predict about molecules?

The three-dimensional shape based on electron pair repulsion

Which of the following molecules is nonpolar due to its geometry, despite having polar bonds?

CO₂

What type of intermolecular force exists between molecules of CH₃OH?

London dispersion, dipole-dipole, and hydrogen bonding

What is the bond angle in a trigonal planar molecule like BF₃?

120°

In a Lewis structure, what do lone pairs on the central atom affect most directly?

Molecular geometry

Which of the following molecules contains a coordinate covalent bond?

NH₄⁺

Transition metals often form colored compounds because:

Electrons transition between d orbitals

What makes transition metals useful as catalysts?

Ability to adopt multiple oxidation states and form complex ions

What is the typical color of compounds containing Cu²⁺ ions?

Blue

Which of the following organic compounds contains a hydroxyl group?

CH₃CH₂OH

Which element would you expect to be a good conductor of electricity?

Copper

Which element forms oxides that are basic in nature?

Calcium

Which group of elements contains members with full outer electron shells?

Noble gases

Which element typically forms +1 ions and is highly reactive?

Potassium

Which of the following elements is most electronegative?

Fluorine

Which of the following elements is considered a metalloid?

Silicon

Which term refers to atoms with the same number of protons but different numbers of neutrons?

Isotopes

Which subatomic particle determines the identity of an element?

Proton

Which element is a metalloid?

Silicon

Which intermolecular force is strongest in water (H₂O)?

Hydrogen bonding

Which molecule contains a polar covalent bond?

HCl

Which principle states that no two electrons in an atom can have the same set of four quantum numbers?

Pauli Exclusion Principle

What causes the emission lines in an atomic spectrum?

Electron transitions between energy levels

Which type of bond involves equal sharing of electrons?

Nonpolar covalent

A gas occupies 4.0 L at 1.0 atm. What will its volume be at 2.0 atm?

2.0 L

Which solute produces the greatest freezing point depression per mole?

NaCl

Which expresses the Ideal Gas Law?

PV = nRT

Which increases solubility of a solid solute in water?

Increasing temperature

According to KMT, gas pressure results from:

Collisions of particles with the container walls

Which describes sublimation?

Solid → Gas

Which condition causes real gases to deviate most from ideal behavior?

High pressure and low temperature

Why are gases compressible but solids are not?

Gas particles are far apart, allowing volume change

Best definition of molarity (M)?

Moles of solute per liter of solution

Which phase has definite volume but no definite shape?

Liquid

Relationship between temperature and kinetic energy in gases?

Temperature is directly proportional to average kinetic energy

Which describes an ideal solution?

Exhibits no heat or volume change upon mixing

Which gas diffuses most rapidly?

Helium

Which intermolecular force is present in all substances?

London dispersion

Flat portions of a heating curve represent:

Phase change with constant temperature

If K < 1, then:

Reactants are favored

Relationship between Kp and Kc?

Kp = Kc(RT)^Δn

Balanced combustion of propane:

C₃H₈ + 5O₂ → 3CO₂ + 4H₂O

Best description of a redox reaction:

A reaction involving electron transfer

Which represents a synthesis reaction?

2H₂ + O₂ → 2H₂O

Which reaction is a neutralization?

HCl + NaOH → NaCl + H₂O

Molar mass of Ca(OH)₂?

74 g/mol

Oxidation number of sulfur in H₂SO₄?

+6

Total number of atoms in 1 mole of H₂O?

3 × 6.022 × 10²³

Correct mole concept statement:

A mole allows chemists to count atoms using mass

Which salt is more soluble in acidic solution?

CaCO₃

Behavior of a strong base in water:

It completely dissociates into ions

Which represents a buffer system?

CH₃COOH and CH₃COONa

Negative ΔG indicates:

The reaction is spontaneous

Hess’s Law allows calculation of:

Overall enthalpy change from known reactions

Sign of ΔS for H₂O(l) → H₂O(g)?

Positive

Which increases rate and effective collisions?

Increasing concentration of reactants

. A catalyst speeds up a reaction by:

Lowering the activation energy

q = mcΔT calculates:

Heat absorbed or released

Rate-determining step:

The slowest step