MSU CEM 141 Final Exam Prep Newest 2026-2027

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MSU CEM 141 Final Exam Prep Newest 2026-2027 Actual Exam With Complete Questions And Correct Detailed Answers (Verified Answers) |Already Graded A+

Sketch of a potential energy curve (text description) - ANSWER-PE decreases as atoms approach, reaches a minimum (stable), rises sharply when too close.

Why do noble gases only form LDFs? - ANSWER-Full valence shells → no stable covalent bonds; only temporary e⁻ fluctuations → LDFs.

LDF strength increases with what? - ANSWER-Size of electron cloud & polarizability.

Higher LDFs → higher what? - ANSWER-Boiling point and melting point.

What is a mole? - ANSWER-6.022×10²³ particles; allows converting between microscopic & macroscopic amounts.

Why use moles instead of mass in equations? - ANSWER-Reactions occur between particles, not grams; moles count particles.

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Steps for limiting reactant problems (concept card) - ANSWER-Convert to moles → use coefficients → smallest product amount = LR.

What is percent yield? - ANSWER-(Actual yield ÷ theoretical yield) × 100%.

Balanced equation meaning - ANSWER-Atom count conserved on both sides; coefficients represent particle ratios.

Diagram description: molecular rearrangement - ANSWER-Reactant

molecules break bonds; atoms rearrange; new product molecules form.

Relationship between λ - ANSWER-ν, and c,c = λν.

Energy of a photon equation - ANSWER-E = hν = hc/λ.

Wave properties of EM radiation evidence - ANSWER-Diffraction and interference patterns.

Particle properties evidence - ANSWER-Photoelectric effect: electrons

emitted only if frequency above threshold.

Photoelectric threshold meaning - ANSWER-Minimum frequency needed to eject electrons, regardless of intensity.

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