AP Chemistry FRQ Room

Analysis of Energy Transitions in the Bohr Model

A researcher is studying the Bohr model of the hydrogen atom. Consider an electron that transitions

Calculations Using the Ideal Gas Law

A researcher studies the behavior of nitrogen gas under non-standard conditions. A sample of nitroge

Effects of Shielding on Atomic Radius

In an atomic physics study, the researcher examines how inner electrons affect the size of the atom

Electron Configuration and Periodic Trends

Use electron configuration and periodic trends to predict element properties and reactivity.

Electron Configuration Anomalies: Case of Copper

Copper has an unusual electron configuration due to stability considerations. Answer the following:

Electronegativity Trends Analysis

A table provides electronegativity values for elements across period 2. The hypothesis is that as yo

Ideal Gas Law Application under Non-STP Conditions

A gas is contained in a 2.00 L vessel at an initial pressure of 1.50 atm and temperature of 350 K. C

Impact of Electron Shielding on Successive Ionization Energies

A researcher evaluates the role of electron shielding in determining the energies required to remove

Le Chatelier’s Principle in Industrial Equilibrium

Consider an industrial equilibrium reaction involving gaseous reactants and products. The graph prov

Mass Spectrometry Analysis of Selenium Isotopes

Given the following table of selenium isotopes, compute the weighted average atomic mass and compare

Mass Spectrometry and Isotopic Ratios

This question explores the determination of atomic mass using mass spectrometry data and the concept

Mass Spectrometry of Selenium Isotopes

A laboratory uses mass spectrometry to analyze selenium and determine its isotopic abundances. The m

Molarity and Solution Concentration Determination

This question explores the calculation of molarity and its relevance in chemical reactions.

Molarity in Reaction Kinetics

In a kinetics lab, the concentration of an acid solution is monitored during a titration experiment.

Percent Composition of Calcium Nitrate

You will calculate the percent composition by mass for the compound calcium nitrate, Ca(NO₃)₂.

Periodic Trends and Atomic Structure Analysis

A researcher is investigating periodic trends by examining how atomic radius and ionization energy v

Photoelectron Spectroscopy Analysis

This question analyzes a photoelectron spectrum (PES) to deduce information about the electronic str

Precipitation Reaction and Ksp Determination with Misapplied Equilibrium Assumptions

An experiment is conducted to determine the solubility product (Ksp) of silver chloride by mixing kn

Predicting Ionic Charges Based on Periodic Trends

In a reaction experiment, compounds form according to the predicted ionic charges based on periodic

Reaction Enthalpy and Thermochemistry

Consider the reaction: $$CH_4 + 2\,O_2 \rightarrow CO_2 + 2\,H_2O$$. Using the standard enthalpies o

Relationship Between Bond Enthalpy and Electronegativity Differences

Bond enthalpy is influenced by the difference in electronegativity between the bonded atoms. Design

Valence Electrons and Periodic Trends

Answer the following questions regarding the electron configurations of nonmetal elements:

Validating the Aufbau Principle Through Spectroscopic Analysis

The Aufbau principle describes the order in which electrons fill atomic orbitals. Design an experime

Analyzing Conductivity Across Bond Types

A researcher compiles data on the electrical conductivity of various compounds—ionic, molecular, net

Application of Coulomb's Law in Ionic Bonding

Using Coulomb's law, analyze the factors that affect the strength of ionic bonds in solids. Answer t

Bond Order, Bond Length, and Experimental Correlations

This question explores the theoretical relationship between bond order, bond length, and bond energy

Bonding and Electrical Conductivity Analysis

A recent study investigates the relationship between bonding type and electrical conductivity in var

Bonding Type and Solubility

The type of bonding in a substance can significantly influence its solubility in various solvents. A

Experimental Design: Identifying Bonding Types via Conductivity

Design an experiment that uses conductivity measurements to determine the bonding type of an unknown

Formal Charge Calculation in Nitrate Ion

The nitrate ion (NO3⁻) exhibits resonance, which affects how formal charges are distributed among th

FRQ 3: Covalent Bonding – Resonance and Formal Charge Analysis

Examine the provided stimulus depicting multiple resonance forms of the carbonate ion (CO3^2-). In y

FRQ 7: Lewis Dot Structures – Expanded and Incomplete Octets

Consider two molecules: one that exhibits an incomplete octet (such as BF₃) and one that exhibits an

FRQ 15: Determining Bond Order from Resonance Structures

A molecule with multiple resonance structures is described in the stimulus. In your answer, (a) desc

Infrared Spectroscopy Misapplication for Determining Molecular Geometry

A researcher uses infrared spectroscopy to deduce the molecular geometry of a complex organic molecu

Ionic Size Effects on Lattice Energy

The lattice energy of ionic compounds is influenced by both the charge of the ions and their ionic r

Melting Point Investigation in Ionic Solids

A researcher studies the melting points of various ionic solids to understand the factors that influ

Metallic Bonding and 'Sea of Electrons' Explanation

Delve into the characteristics of metallic bonding using the 'sea of electrons' model to explain the

Molecular Covalent Bonding: Sigma and Pi Bonds

Explore the characteristics of molecular covalent bonding by analyzing sigma and pi bonds in a molec

Network Covalent Bonds in Diamond and Graphite

A materials scientist is comparing the network covalent structures of diamond and graphite to unders

Resonance and Bond Order in the Nitrate Ion

A research group is studying the nitrate ion ($$\text{NO}_3^{-}$$) to understand how resonance stabi

Thermal Conductivity and Bonding: A Comparative Study

A study is conducted to correlate thermal conductivity with the type of bonding in various solids. A

Analysis of Chromatography Retention Factors in Solvent Systems

Investigate the effect of compound polarity on retention factors in a paper chromatography experimen

Analysis of Ink Components Using Retention Factors

A study is conducted to separate the components of black ink using paper chromatography. The separat

Application of Coulomb's Law to Lattice Energy

Examine the role of Coulombic forces in the formation of ionic lattices and the implications for mel

Application of the Ideal Gas Law Under Non-Ideal Conditions

A student performs an experiment to study the behavior of a gas by applying the ideal gas law, $$PV

Assessment of Phase Transition Analysis Based on Intermolecular Forces

A student conducts an experiment to measure the phase transition temperatures (melting and boiling p

Column Chromatography and Separation of Mixtures

A chemist is using column chromatography to separate a mixture of compounds with varying polarities.

Column Chromatography for Dye Separation

A laboratory technician aims to separate a mixture of dyes using column chromatography. The separati

Derivation of Kinetic Molecular Theory Relationships

Kinetic molecular theory links temperature with molecular kinetic energy. Derive the relationships a

Effect of Temperature on Gas Volume

According to Charles' Law, the volume of a gas increases with temperature at constant pressure. (a)

Effusion Rate Analysis Using Graham’s Law

Effusion is the process by which gas molecules escape through a small opening. Graham's Law, express

Energy Transition in the Electromagnetic Spectrum

Calculate the energy change for an electron transitioning between energy levels when absorbing light

Evaluation of Gas Density Measurements under Deformable Container Conditions

A student conducts an experiment to determine the density of a gas using the equation $$D = \frac{m}

Gas Density and Molar Mass Calculation

Determine the density of a gas and use it to calculate its molar mass, then propose an identity for

Gas Density and Molar Mass Determination

A material scientist measures the density of an unknown gas at specific conditions to infer its mola

Ideal Gas Law and Density Derivations

The ideal gas law can be manipulated to derive useful expressions for properties like density. Work

Ideal Gas Law and Stoichiometry

A 10.0 L container is said to hold a mixture of three gases at 1.00 atm and 298 K: 0.50 mol of hydro

Investigating Ideal Gas Behavior and Deviations

A set of experiments was conducted to measure the pressure of an ideal gas at various temperatures.

Molecular Geometry and Polarity Exceptions

This question asks you to analyze how molecular geometry and the presence of lone pairs affect molec

Molecular Geometry and Polarity in NF3 versus NH3

Compare the molecular structures of NF3 and NH3 to determine how geometry and electronegativity infl

Paper Chromatography Analysis

A researcher employs paper chromatography to separate the components of an ink mixture. Using the pr

Paper Chromatography and Polarity

Analyze the separation of an ink mixture using paper chromatography and relate the retention factor

Paper Chromatography Separation of Pigments

In paper chromatography, the separation of mixture components depends on solute–solvent polarity int

Solvent Polarity and Dipole Interactions

The solubility of substances depends heavily on the intermolecular forces present. A polar solute ge

Vibrational Energy Transitions

The energy absorbed during a vibrational transition in a molecule is given by $$E = h*v$$, where h i

Vibrational Spectroscopy and Molecular Polarity

Utilize IR spectroscopy data to identify characteristic vibrational modes in polar molecules and dis

Acid-Base Neutralization Reaction and pH Calculation

In a titration experiment, 50.00 mL of 0.100 M acetic acid (HC2H3O2) is neutralized with 0.100 M NaO

Analysis of Titration Data: Determining the Unknown Concentration

In a titration experiment, 20.0 mL of an unknown monoprotic acid is titrated with 0.1 M NaOH. The eq

Analyzing Redox Titration using KMnO4

In a redox titration, an iron(II) solution is titrated with 0.0200 M potassium permanganate (KMnO4)

Assessing Percent Error in Stoichiometric Calculations

Design an experiment to compare the theoretical and experimental yields in a synthesis reaction and

Atmospheric Ozone Formation and Decomposition

In the Earth's stratosphere, oxygen molecules can absorb ultraviolet (UV) light and split into indiv

Balancing a Complex Chemical Equation with Multiple Reactants

Balance the following chemical equation using the ion-electron (half-reaction) method: $$KClO_3 + H

Balancing Chemical Equations and Percent Error Calculation

This FRQ covers balancing chemical equations and percent error analysis. You are provided with a rea

Buffer Preparation and pH Calculation

A buffer solution is made by mixing 0.50 moles of acetic acid ($$HC_2H_3O_2$$) with 0.25 moles of so

Combustion Reaction Mechanisms and Energy Calculations

Butane ($$C_4H_{10}$$) combusts according to the reaction: $$C_4H_{10} + \frac{13}{2} O_2 \rightarro

Decomposition Reaction Analysis

A compound AB undergoes thermal decomposition according to the reaction $$AB \rightarrow A + B$$. In

Designing an Experiment for Acid-Base Buffer Systems

A researcher investigates the buffer capacity of a solution composed of acetic acid (HC₂H₃O₂) and it

Determination of Oxidation States

Assign oxidation states to the elements in the following compounds:

FRQ 12: Interpreting a Graph of Reaction Kinetics

A graph is provided showing the natural logarithm of the reactant concentration (ln[A]) versus time

Gravimetric Analysis of Unknown Alkali Hydroxide

A 4.33 g sample of an unknown alkali hydroxide (LiOH, NaOH, or KOH) is dissolved in water. Adding a

Investigation of Synthesis Reaction Yield

An experiment was conducted to study a synthesis reaction represented by A + B → AB under varying te

Limiting Reactant and Reaction Yield Calculation

In a neutralization reaction, 10.0 mL of 0.500 M HCl is mixed with 15.0 mL of 0.300 M NaOH according

Percent Error Analysis in Reaction Yield

In three separate reaction trials, the experimental yield and theoretical yield were recorded. Revie

Polymer Chemistry: Reaction Mechanisms in Polymerization

Polyethylene is produced by the radical polymerization of ethene (C2H4) under high pressure and temp

Precipitate Stability: Effect of pH on Solubility of Copper Hydroxide

The solubility of $$Cu(OH)_2$$ is highly dependent on the pH of the solution. Design an experiment t

Precipitation Reaction and Solubility Rules

In an experiment involving the mixing of various aqueous salt solutions, a researcher observes the f

Precipitation Reaction: Mechanism Identification

In an experiment, two aqueous solutions were mixed and a solid precipitate was observed to form. Add

Quantitative Analysis of a Precipitation Reaction

Barium chloride (BaCl2) reacts with sodium sulfate (Na2SO4) to produce a precipitate of barium sulfa

Quantitative Analysis of Combustion in Hydrocarbons

A 1.50 g sample of an unknown hydrocarbon is combusted, producing 3.30 g of $$CO_2$$ and 1.35 g of $

Reaction Rate Analysis through Graphical Data Interpretation

A researcher measures the concentration of a reactant during a decomposition reaction over time to a

Redox Titration Analysis Using KMnO4

In a redox titration, potassium permanganate ($$KMnO_{4}$$) is used to determine the concentration o

Redox Titration: KMnO4 and Oxalate Reaction

A student performs a redox titration using potassium permanganate ($$KMnO_4$$) as the titrant to det

Synthesis Reaction and Stoichiometric Calculations

An industrial process synthesizes compound AB via the reaction $$A + B \rightarrow AB$$. In a partic

Synthesis Reaction for a Complex Salt

A laboratory procedure is designed to synthesize a complex salt by reacting a metal oxide with a car

Titration of a Polyprotic Acid

A 0.10 M solution of a polyprotic acid is titrated with 0.10 M NaOH. The following titration data we

Analysis of Collision Theory and Reaction Energy Profile

Collision theory provides an explanation for the observed rate of reaction, and an energy profile di

Catalysts and Reaction Mechanisms

Consider the overall reaction $$A + B \to C$$ which proceeds via the following two-step mechanism:

Collision Theory: Effects of Concentration and Temperature

Collision theory explains many aspects of how reaction rates change. Answer the following parts.

Comprehensive Analysis Using Arrhenius Equation and Temperature Variation

A series of experiments provided the following rate constants at different temperatures for a partic

Deriving Integrated Rate Law from Differential Equations for a First Order Reaction

Given the differential rate equation for a first order reaction, $$\frac{d[A]}{dt} = -k*[A],$$ answe

Designing a Controlled Kinetic Experiment

Design an experiment to determine the rate law for a reaction between reactants A and B. Your experi

Designing an Experiment to Determine a Reaction's Rate Law

You are tasked with determining the rate law for the reaction $$X + Y \rightarrow Z$$. Design an exp

Determination of First-Order Reaction Rate from Time-Concentration Data: Unit Conversion Error Analysis

A chemist conducted an experiment to determine the rate constant for a first-order reaction by plott

Determining Activation Energy using the Arrhenius Equation

A reaction was studied at two different temperatures. At $$T_1 = 300\,K$$, the rate constant is $$k_

Determining Reaction Mechanisms from Isotope Labeling Experiments

A researcher uses isotopically labeled reactants to study the mechanism of a complex reaction. The f

Effect of Pressure on the Rate Law in Gaseous Reactions

A gaseous reaction follows the rate law written in terms of partial pressures: $$\text{Rate} = k\,P_

Effect of Solvent Polarity on Reaction Kinetics

A reaction is performed in two different solvents: one polar and one non-polar. The measured rate co

Evaluating Alternative Reaction Mechanisms

Two mechanisms have been proposed for the reaction $$\text{A} + \text{B} \rightarrow \text{C}$$: Me

Graphical Determination of Half-Life for First Order Reactions

The half-life of a first order reaction is constant and can be determined from a plot of $$ln[A]$$ v

Graphical Determination of Kinetic Order from Concentration Data

The concentration of reactant A in a reaction is measured over time. Use the data provided to determ

Identification of the Rate-Determining Step

A multi-step reaction has been proposed with the following mechanism: Step 1 (fast): $$A + B \to I$

Initial Rate Method with Multiple Reactants

For the reaction $$A + B \to C$$, the following data (obtained using the initial rate method) were r

Integrated Rate Law Analysis for a Second Order Reaction

A second order reaction was investigated by monitoring the concentration of reactant A over time. Th

Investigating Half-Life in First-Order Reactions

A research team monitored a first-order reaction by recording the concentration of reactant A over t

Investigation of an Intermediate in a Multi-Step Reaction

A reaction proceeds through the following mechanism: Step I: $$A \rightarrow X$$ (fast) Step II: $

Investigation of Kinetic Isotope Effects on Reaction Rates

An experiment is designed to compare the reaction rates of a compound and its deuterated analogue. A

Investigation of Rate Law using Initial Concentration Measurements: Error Analysis

A research team investigated the reaction $$A + 2*B + C \rightarrow D$$ by measuring the initial rat

Kinetic Data Analysis from Concentration vs Time Table

A series of experiments provided concentration data for reactant A over time. Analyze the data to de

Kinetic Isotope Effect Analysis

The kinetic isotope effect (KIE) is observed when a hydrogen atom in a reactant is replaced by deute

Molecular Orientation and Reaction Rates

Collision theory states that in addition to sufficient energy, reactant molecules must have the corr

Multi-Reactant Order Determination

The reaction $$A + 3B \to \text{Products}$$ was studied and the following data were collected: | Ex

Rate Law Determination from Experimental Data

A series of experiments were conducted on the reaction A + 2B + C → D. The initial concentrations an

Analyzing a Two-step Reaction: Applying Hess’s Law

A researcher asserts that a complex reaction can be decomposed into two steps, with the overall enth

Application of Hess's Law in a Multi-step Reaction

A researcher is studying a reaction with overall equation $$X + Y \rightarrow Z$$. The reaction is b

Bomb Calorimetry and Reaction Enthalpy Determination

Bomb calorimetry is used to accurately measure the enthalpy change of combustion reactions. Explain

Bond Energy Calculation

Calculate the energy required to break all the H-O bonds in 2 molecules of water (H₂O), given that e

Bond Energy Calculation via Combustion Reaction

A student performs an experiment to calculate the overall reaction enthalpy for a combustion reactio

Calorimetry and Specific Heat Calculation

A student conducts an experiment using a calorimeter to measure the specific heat of an unknown meta

Catalyst Effect on Reaction Mechanism

A reaction can proceed by two pathways: one with a catalyst and one without. The energy diagram show

Combustion Reaction Enthalpy

Examine the combustion reaction of propane. Use standard enthalpy of formation values to calculate t

Determining Enthalpy of Fusion from Calorimetry Data

A calorimetry experiment is performed where 50.0 g of ice at 0°C absorbs energy and completely melts

Determining Overall Reaction Enthalpy Using Hess's Law

A reaction is carried out in two steps: Step 1: $$A → B$$, ΔH = +50 kJ Step 2: $$B → C$$, ΔH = -80 k

Determining Reaction Enthalpy from Bond Energies

A claim is made that the enthalpy change of a reaction can be accurately determined by using average

Energy Diagram and Reaction Mechanism Analysis

An energy diagram of a two-step reaction shows: Step 1 with an activation energy of 50 kJ/mol leadin

Energy Transfer in Phase Changes: Melting and Vaporization

A researcher studied the energy transfer during phase changes by heating a sample until it melted an

Investigating the Effect of Temperature on Reaction Rate and Enthalpy Measurement

In a reaction study, the concentration of a reactant was monitored over time, and the following obse

Molecular Kinetics and Reaction Energy Transfer

During a chemical reaction, observations indicate changes in the kinetic energy distribution of mole

Multi-Step Enthalpy Calculation Using Hess's Law

A complex reaction can be broken into three steps as shown below: Step 1: $$A + B \rightarrow C$$, $

Phase Change & Enthalpy Calculations

A researcher investigates the energy required for a substance to undergo both melting and vaporizati

Phase Change Thermodynamics: Melting and Vaporization

Consider the following phase change enthalpy values: | Phase Change | Enthalpy (kJ/mol) | |----

Phase Diagram Analysis and Thermodynamics

A phase diagram for an unknown substance is provided, showing the boundaries between solid, liquid,

Specific Heat Capacity and Heat Transfer in Everyday Materials

In an experiment, the temperature change of water and a metal cup were recorded under identical heat

Study of Phase Transition: Quantifying Enthalpy of Fusion

An experiment was conducted to measure the enthalpy of fusion for a substance. A sample of Substance

Thermodynamics of Reaction Pathways: Investigating Multiple Reaction Channels

A decomposition reaction can proceed via two competing pathways. A table lists the fraction of the r

Acid Dissociation Constant and Equilibrium Analysis

Consider the dissociation of a weak acid, HA, in water: $$HA(aq) \rightleftharpoons H^{+}(aq) + A^{-

Analyzing Kp and Kc in Gas-Phase Equilibria

A researcher studies the gaseous reaction: $$2*X(g) + Y(g) ⇌ 3*Z(g)$$. Considering the relationship

Base Dissociation Constant (Kb) of Ammonia: Error in Water Concentration Assumption

In an experiment to determine the base dissociation constant (Kb) for ammonia, the reaction $$NH_3 +

Common Ion Effect and Solubility Product

Silver chloride (AgCl) dissolves according to the equilibrium: $$AgCl(s) \rightleftharpoons Ag^+(aq)

Constructing Equilibrium Expressions and Unit Analysis

For the heterogeneous reaction $$\text{CaCO}_3 (s) \leftrightharpoons \text{CaO} (s) + \text{CO}_2 (

Conversion from Kc to Kp in Gas-Phase Equilibria

In the reaction $$2A (g) \rightleftharpoons B (g) + C (g)$$, experimental measurements provide value

Designing a Reaction Vessel Experiment for Yield Optimization

An industrial chemical process involves a reversible reaction whose yield depends on pressure, tempe

Dilution Effects on Aqueous Equilibria

Consider the following equilibrium in an aqueous solution: $$Fe^{3+}(aq) + SCN^{-}(aq) \leftrighthar

Dilution Impact on Aqueous Equilibrium

A research team is studying the equilibrium for the reaction $$Fe^{3+} + SCN^{-} ⇌ FeSCN^{2+}$$ in a

Effect of Catalysts on Equilibrium Dynamics

Investigations were conducted on the reaction D ⇌ E + F to compare the time required to reach equili

Effect of Catalysts on Reaction Equilibrium

Consider the equilibrium reaction: $$E (g) + F (g) \rightleftharpoons G (g)$$. Analyze the impact of

Effect of Pressure Changes on Gaseous Equilibria

A gaseous equilibrium reaction is represented by $$2*X(g) + Y(g) \rightleftharpoons 3*Z(g)$$. An exp

Equilibrium Behavior Under Non-Ideal Conditions

In real solutions, non-ideal behavior such as ionic strength can affect the measured equilibrium con

Equilibrium in Heterogeneous Systems

Discuss the treatment of heterogeneous equilibria in writing equilibrium constant expressions and pr

Evaluating Reaction Direction Using Reaction Quotient (Q)

Design an experiment to evaluate the reaction direction during the conversion of sulfur dioxide to s

Evaluating Temperature Influence on $$K_{eq}$$

Temperature changes can alter the equilibrium constant of a reaction. Answer the following:

Examining the Role of Catalysts in Equilibrium

Catalysts are known to affect reaction rates without changing the equilibrium constant (Keq). Answer

Experimental Design: Determining Ksp of a Sparingly Soluble Salt

Design an experiment to determine the solubility product constant (Ksp) of a sparingly soluble salt

Experimental Determination of $$K_c$$ for HI Decomposition

Consider the decomposition of hydrogen iodide (HI): $$2HI (g) \rightleftharpoons H_2 (g) + I_2 (g)$$

Exploring Equilibrium Expressions

For the general reaction $$a*A + b*B \leftrightarrow c*C + d*D$$, answer the following parts.

Graphical Analysis of Equilibrium Shifts Under External Stress

A graph displays the concentration of species versus time for a reversible reaction that has been pe

Haber Process Equilibrium Analysis

Analyze the equilibrium behavior in the Haber process: $$N_2 + 3*H_2 \leftrightarrow 2*NH_3$$. Deter

Haber Process Equilibrium Analysis

Examine the equilibrium for ammonia production represented by the reaction $$\rm N_{2}(g) + 3*H_{2}(

Haber Process Equilibrium Calculation

In the Haber process, $$N_2 + 3*H_2 \leftrightarrow 2*NH_3$$, a container initially contains $$[N_2]

Impact of Dilution on Ion Concentrations in Equilibrium

In the equilibrium system $$Fe^{3+}(aq) + SCN^{-}(aq) \rightleftharpoons FeSCN^{2+}(aq)$$, a researc

Impact of External Inert Gas Addition on Equilibria

Consider the equilibrium reaction: $$\ce{2A (g) <=> B (g)}$$. Investigate the effect of adding an in

Impact of Temperature Change on an Exothermic Reaction

The reaction $$\rm N_{2}(g) + 3H_{2}(g) \rightleftharpoons 2NH_{3}(g) + \text{energy}$$ is exothermi

Industrial Equilibrium Optimization: Haber Process Revisited

A chemical plant seeks to optimize ammonia production via the Haber process. The reactor design must

Interconversion Between Kc and Kp

For the gas-phase equilibrium reaction $$N_2O_4 (g) \leftrightharpoons 2*NO_2 (g)$$, answer the foll

Investigating Le Chatelier's Principle: A Lab Simulation

A lab simulation is performed on the reaction: $$\ce{A (aq) + B (aq) <=> C (aq)}$$ by varying the co

Linking Reaction Kinetics and Equilibrium

In the reversible reaction $$2Y(g) \rightleftharpoons Z(g)$$, equilibrium is reached when the rates

Manipulating Equilibrium Constants Using Hess's Law

Use Hess’s law to derive an overall equilibrium constant from a series of reactions and explain how

Manipulation of Equilibrium Constants via Reaction Reversal and Scaling

For the reaction: $$A+B ⇌ C$$, a researcher knows that the equilibrium constant $$K$$ is 8.0. Answer

Manipulations of Equilibrium Constants using Hess's Law

Examine how equilibrium constants transform when the reaction is manipulated. Answer the following p

Measuring Equilibrium Constant in a Gas Phase Reaction

Design an experiment to determine the equilibrium constant $$K_p$$ for the gaseous reaction: $$\math

Noble Gas Effects on Reaction Equilibrium

Consider the gaseous reaction $$A(g) + B(g) \leftrightharpoons C(g)$$. Answer the following parts re

Optimization Strategies in the Haber Process

Discuss various methods employed in industrial settings to maximize the yield of ammonia in the Habe

Precipitation Reaction Analysis: Mixing of Solutions

A solution of 0.050 M Na$_2$SO$_4$ is mixed in equal volumes with a 0.10 M BaCl$_2$ solution. Barium

Predicting Shifts in Complex Ion Formation Equilibria

Consider the complex ion formation equilibrium: $$\ce{Cu^{2+} (aq) + 4NH3 (aq) <=> [Cu(NH3)_4]^{2+}

Pressure Changes and Their Impact on Equilibria in Gaseous Reactions

For the gaseous reaction: $$2J(g) + K(g) \rightleftharpoons 3L(g)$$, consider how changes in externa

Pressure Effects on Gaseous Equilibrium

Consider the gaseous equilibrium: $$\mathrm{N_2O_4 (g) \rightleftharpoons 2NO_2 (g)}$$. Answer the f

Reaction Quotient (Q) versus Equilibrium Constant (K)

For the reaction W ⇌ X, initial experimental measurements yield [W] = 0.20 M and [X] = 0.10 M, with

Reaction Quotient (Q) vs Equilibrium Constant (Keq)

For the reaction $$2H_2 (g) + O_2 (g) \rightleftharpoons 2*H_2O (g)$$, initial concentrations are gi

Reaction Quotient and Equilibrium Dynamics

Consider the equilibrium reaction $$N_2 + 3 * H_2 \rightleftharpoons 2 * NH_3$$ under the initial co

Reaction Stoichiometry and Equilibrium

Consider the reaction: $$2A + B \rightleftharpoons 3C$$. Answer the following parts:

Relating Concentration and Pressure Equilibrium Constants

Differentiate between the concentration-based equilibrium constant $$K_c$$ and the pressure-based eq

Solid Marker in Reaction Quotient Calculation Error

A researcher investigates the equilibrium for the reaction $$L(s) + M(aq) ⇌ N(aq)$$ by measuring the

Solubility and the Common Ion Effect

Investigate the dissolution of AgCl and the influence of the common ion effect. Answer the following

Solubility Product (Ksp) Calculation

For the sparingly soluble salt $$MX_2 (s) \rightleftharpoons M^{2+} (aq) + 2*X^{-} (aq)$$ with $$K_{

Solubility Product and Precipitation: Calculation Challenge

Consider the dissolution of calcium fluoride: $$CaF_2(s) \leftrightharpoons Ca^{2+}(aq) + 2*F^{-}(aq

Temperature Effects on Exothermic Equilibrium Reactions

Consider the exothermic ammonia synthesis reaction: $$\ce{N2 + 3*H2 <=> 2*NH3}$$ with $$\Delta H = -

Van't Hoff Analysis: Temperature and Equilibrium Constant

For an exothermic reaction, equilibrium constants (Kc) were measured at various temperatures as prov

Buffer Capacity and Dilution Effects

A buffer system consisting of acetic acid and sodium acetate is under investigation to understand it

Buffer Capacity and pH Change

Three buffer solutions are prepared with the following compositions: Buffer A: 0.50 M acetic acid a

Buffer Capacity Experiment in River Water

An environmental scientist aims to determine the buffer capacity of river water affected by urban ru

Buffer Design for Pharmaceutical Applications

In pharmaceutical formulations, maintaining a stable pH is critical. A formulation is designed to ha

Buffer Response to Acid Addition

A buffer solution is prepared by mixing 0.25 M acetic acid (HC₂H₃O₂) with 0.25 M sodium acetate (NaC

Buffer System and Henderson–Hasselbalch Applications

A buffer solution is prepared by mixing acetic acid (HC2H3O2) and sodium acetate (NaC2H3O2). The pKa

Calculations on pOH and pH for a Weak Base

A weak base, B, is dissolved in water, partially reacting to form its conjugate acid, HB+. Given tha

Comparative Acid Strengths: Binary vs. Oxoacids

Acid strength varies depending on molecular structure. Answer the following:

Designing a Titration Experiment to Determine Weak Acid Concentration

This FRQ involves designing a titration experiment to determine the concentration of a weak acid usi

Determining pKb from a Known pKa

A study of conjugate acid-base pairs involves using the relation $$pK_a + pK_b = 14$$. For acetic ac

Equilibrium Analysis of a Weak Acid

Analyze the equilibrium of a weak acid's dissociation in water using an ICE table.

Impact of pH on Solubility of Mg(OH)2

This FRQ investigates how solution pH affects the solubility of the sparingly soluble hydroxide salt

Impact of Temperature on Kw and pH of Pure Water

The autoionization of water is described by the equilibrium $$H_2O (l) \rightleftharpoons H^+ (aq) +

Indicator Behavior in Titration

During a titration experiment, an indicator is used to detect the equivalence point. Analyze the rol

Indicator Behavior in Titration

Discuss the role of pH indicators in titration experiments. Describe the necessary properties of an

Industrial pH Adjustment in Wastewater Treatment

A wastewater treatment plant is tasked with neutralizing acidic effluent before discharge. The efflu

Interpreting pH Variability in Environmental Waters

A researcher collects pH data from several lakes, finding values ranging from 6.2 to 8.4. Discuss th

Misinterpretation of Neutralization Endpoints in Mixed Acid Systems

A student performed a titration on a solution containing a mixture of HCl (a strong acid) and acetic

Net Ionic Equations in Neutralization Reactions

Consider the reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) in aqueous solutio

Neutralization Reaction Error in Weak Base Titration

A student performed a titration of ammonia (NH₃), a weak base, with a strong acid (HCl). The student

Neutralization Reaction in a Weak Acid-Strong Base System

A lab experiment investigates the titration of acetic acid (HC2H3O2) with sodium hydroxide (NaOH) in

pH Calculation for Strong Acid Solutions

A scientist prepares a 0.0100 M HCl solution. Since HCl is a strong acid, it completely dissociates

Polyprotic Buffer Misapplication in pH Control

For a biochemical assay, a researcher attempted to prepare a buffer solution using phosphoric acid (

Strong Acid pH Calculation and Analysis

A researcher prepares a 0.01 M HCl solution and uses it to explore the concept of pH in strong acids

Temperature Effects on Water Ionization (Kw)

In an experiment, water samples are heated to different temperatures and the ionization constant of

Titration of a Weak Acid with a Strong Base: Acetic Acid and NaOH

In a titration experiment, 0.10 M acetic acid (HC₂H₃O₂) is titrated with 0.10 M sodium hydroxide (Na

Using an ICE Table for pH Calculation of a Weak Acid

Acetic acid, a weak acid, partially dissociates in water. Consider a 0.1 M acetic acid solution with

Calculating Galvanic Cell Potential

A galvanic cell is constructed using the following half-reactions at 25°C: $$\text{Zn}(s) \rightarro

Combined Kinetic and Thermodynamic Analysis: Confounding Variables

A researcher designed an experiment to study both the reaction rate and thermodynamic favorability o

Coupled Reactions in Industrial Processes

In an industrial process, an endothermic reaction that is non-spontaneous is coupled with an exother

Designing a Galvanic Cell

A galvanic cell is constructed using a copper electrode immersed in 1 M CuSO₄ and a zinc electrode i

Designing a Multi-step Redox Reaction Experiment

A researcher aims to investigate a multi-step redox reaction that involves an intermediate species.

Designing an Experiment to Measure Entropy Change

Design a laboratory experiment that aims to measure the entropy change when mixing two aqueous solut

Electrolysis and Electroplating Calculation

In an electroplating experiment, metal X (molar mass $$50.0\,g/mol$$, valence +2) is deposited on a

Entropy and Reaction Disorder Analysis

This question examines the concept of entropy change and reaction disorder in chemical reactions.

Entropy Change Analysis

A researcher investigates standard entropy changes (∆S°) using various chemical reactions under stan

Entropy Change in Phase Transitions

A pure substance undergoes two phase transitions: fusion (melting) and vaporization. The measured en

Entropy Changes in Metabolic Reactions

Glycolysis, the metabolic pathway converting glucose to pyruvate, involves multiple steps that produ

Exploring the Nernst Equation in Dynamic Systems

A series of measurements was taken to study the effect of ion concentration on cell potential.

FRQ 2: Temperature Dependence of Gibbs Free Energy

Consider a reaction for which the standard enthalpy change is \(\Delta H^\circ = -100\,kJ/mol\) and

FRQ 13: Calculating Deposited Mass in Electroplating

In an electroplating experiment, silver is deposited according to the reaction: $$Ag^+ + e^- \right

FRQ 14: Determining Reaction Spontaneity from Reduction Potentials

A cell is constructed using the following half-reactions with their standard reduction potentials:

Galvanic Cell Performance Over Time

Experimental data for a galvanic cell is presented in the table below, showing a decrease in cell po

Gibbs Free Energy under Non-Standard Conditions

An experiment examines how deviations from standard conditions affect the cell potential in an elect

Graphical Analysis of Reaction's Voltage Decay

A galvanic cell's voltage is recorded over time. Analyze the following graph:

Influence of Temperature on Gibbs Free Energy

Design an experiment to study how temperature affects the Gibbs free energy (ΔG°) of an endothermic

Interpreting Gibbs Free Energy from Reaction Spontaneity Reports

A study reports that a reaction with $$\Delta H° = +50\;kJ/mol$$ and $$\Delta S° = +100\;J/mol\cdot

Phase Change and Entropy Variation

A scientific claim states that reactions converting a gas to a liquid always result in a negative ΔS

Quantitative Analysis of Electron Flow in Electrolysis

An electrolytic cell is operated at a current of $$5*A$$ for 600 seconds, and the plating reaction r

Redox Titration and Free Energy

A laboratory experiment involves a redox titration using a galvanic cell to determine the concentrat

Reduction Potential and Overall Redox Reaction

Analyze the overall redox reaction using provided half-reactions and discuss the implications of ele

Temperature Dependence in Galvanic Cell Voltage

A media report suggests that the voltage output of a galvanic cell decreases linearly with increasin

Temperature Dependence of Equilibrium in Redox Reactions

Experimental data for a redox reaction is provided below.

Temperature Influence on Reaction Spontaneity

A reaction has a standard enthalpy change of $$\Delta H° = -80\; kJ/mol$$ and a standard entropy cha