Ochem pp quiz 1

what made organic chemistry seem intimidating before the course began

its reputation

Which course was repeatedly mentioned as another demanding class often taken at the same time

Anatomy and Physiology

Students described which topic as one of the hardest concepts to understand intially

movement of electrons in reactions

besides electrons what additional skill did students find challenging

three-dimensional spatial reasoning

according to the video, the first semester primarily teaches students to…

think differently about molecular structures

students compared learning Ochem to ….

learning a foreign language

Why did students say understanding mechanisms is preferable to memorizing reactions?

Mechanisms support critical thinking during synthesis

Knowing reaction mechanisms helps identify

Likely bases and nucleophiles

One student realized simply repeating homework problems could lead to

Recognizing answers without understanding

When first learning reactions, one student initially focused on:

 Matching reagents to products

 Students recommended using the textbook because it:

Explains concepts in multiple ways

A self-described 'picture person' preferred:

Group lectures only

A favorite study strategy for exams was:

Making flashcards and solving end-of-chapter problems

One student created 'key concept' summaries primarily to:

 Provide quick review sheets

Practice skills assigned after class were used as:

 self-test of understanding

Students generally believed earning an A required:

Substantial practice beyond assigned homework

How far in advance did students commonly recommend beginning serious exam preparation?

Three to seven days before

Approximately how many hours of preparation did one student describe as reasonable?

About 10 hours

Students advised thinking about how the instructor might:

Make practice problems more difficult

According to the closing comments, an important contributor to success was:

Working with dedicated classmates who held each other accountable

Which of the following is a pure compound?

NaCl

How many protons are present in an atom of phosphorus (atomic number 15)?

15

 What is the correct formula for aluminum sulfate?

Al₂(SO₄)₃

Which compound is named iron(III) oxide?

 Fe₂O₃

Which is the ground-state electron configuration of oxygen?

 1s²2s²2p⁴

Which element has the largest atomic radius?

Na

 Which element has the greatest first ionization energy?

Ne

How many unpaired electrons are present in a ground-state nitrogen atom?

3

As you move from left to right across a period, atomic radius generally:

decreases

Which type of bond results from unequal sharing of electrons?

 Polar covalent

How many electron domains surround the central carbon atom in CO₂?

2

What is the molecular geometry of CH₄?

tetrahedral

Which molecule contains a lone pair on the central atom that affects molecular shape?

NH3

Which resonance statement is correct?

Only electrons move in resonance structures.

The hybridization of the carbon atom in ethene (C₂H₄) is:

sp2

How many σ and π bonds are present in N₂?

1 σ, 2 π

Which molecule is expected to be nonpolar overall?

CO2 ; linear geometry

Which Lewis structure rule is most useful for second-row elements

Atoms tend to achieve an octet.

What is the hybridization of the central atom in BF₃?

sp²

Which molecule contains an sp-hybridized carbon atom?

C2H2; CO2

Which intermolecular force is primarily responsible for the high boiling point of water?

Hydrogen Bonding

Which substance is expected to have the weakest intermolecular forces?

CH4

As intermolecular forces increase, the boiling point generally:

increases

Which statement best describes activation energy?

Minimum energy required for reaction

A catalyst increases reaction rate by:

Lowering activation energy

Which factor generally increases the rate of a chemical reaction?

Higher reactant concentration

 On a potential energy diagram, the highest point represents the:

Transition state

If the temperature of a reaction increases, the reaction rate usually:

Increases

According to the Brønsted–Lowry definition, an acid is a substance that:

Donates a proton

Which of the following is a strong acid?

HCl

Which species is the conjugate base of HSO₄⁻?

SO₄²⁻

At 25 °C, a solution with pH = 2 is:

Acidic

Which substance acts as a base in the reaction NH₃ + H₂O ⇌ NH₄⁺ + OH⁻?

NH3

A reaction with a negative ΔH is described as:

Exothermic

Which thermodynamic quantity measures the disorder of a system?

entropy

A reaction is spontaneous under constant temperature and pressure when ΔG is:

Negative

Which statement about chemical equilibrium is correct?

Forward and reverse reactions occur at equal rates.

Increasing the concentration of a reactant at equilibrium will generally:

 Shift equilibrium toward products

Which molecule contains polar bonds but is nonpolar overall due to its geometry?

CO2

Which compound exhibits hydrogen bonding between its molecules?

NH3

 Which element is expected to have the highest electronegativity?

F

Which electron configuration corresponds to a noble gas?

1s²2s²2p⁶

A triple bond consists of:

One σ and two π bonds

Which change will most likely increase the rate of a chemical reaction?

Add a catalyst

Which statement is true for an exothermic reaction?

Products have lower enthalpy than reactants

The conjugate acid of OH⁻ is:

H₂O

 Which species is most likely to form a +2 ion?

Mg

Which combination best predicts that a substance will have a high boiling point?

Strong hydrogen bonding