AP Chemistry FRQ Room

Application of the Ideal Gas Law: Gas Evolution Reaction

A chemical reaction conducted in a closed system produces a gas that is collected at Standard Temper

Atomic Radii and Crystallographic Trends

Interpret experimental data on atomic radii and discuss underlying causes and measurement challenges

Computational Study on Effective Nuclear Charge and Atomic Radius

A computational simulation was performed to study the relationship between effective nuclear charge

Determining Molarity of a Solution

A student dissolves $$5.00\,g$$ of sodium chloride (NaCl) in enough water to make $$250.0\,mL$$ of s

Electron Configuration and Periodic Trends

Consider the electron configurations of elements across a period and the resulting periodic trends.

Electron Configuration Anomalies: Case of Copper

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

Electron Configuration Determination via Photoelectron Spectroscopy

Photoelectron spectroscopy (PES) is used to probe the energies of electrons in an atom, providing in

Electron Configuration Diagram Analysis

Given the electron configuration diagram for elements in the third period, identify the element with

Electrostatic Attraction and Atomic Energy Levels

Discuss the role of Coulomb's law in atomic interactions and link it to discrete energy levels obser

Empirical and Molecular Formula Determination

A newly discovered compound is analyzed and found to contain 56.5% carbon, 7.11% hydrogen, and 36.4%

Evaluating Electronegativity Differences by Measuring Bond Energies

Electronegativity differences between atoms affect the bond energy in diatomic molecules. Design an

Exploring Molarity and Reaction Stoichiometry

In a titration experiment, 25.0 mL of 0.10 M hydrochloric acid (HCl) is titrated with 0.10 M sodium

Gas Law Applications in Reaction Kinetics

Apply the ideal gas law to analyze gas-phase reactions and discuss deviations from ideal behavior.

Integrated Chemical Problem: Reaction Stoichiometry, Molarity, and Gas Volume

Consider the decomposition reaction of sodium azide: $$2 * NaN_3 \to 2 * Na + 3 * N_2$$. Answer the

Ionization Energy Determination Experiment with Overlooked Electron Screening

In an experiment to measure the ionization energy of a multi-electron atom using photoelectron spect

Kinetic Energy of an Ejected Electron

In photoelectron spectroscopy, when a photon ejects an electron, the energy of the photon is consume

Percent Composition and Empirical Formula Determination

A compound is analyzed and found to have the following percent composition by mass: $$40.0\%$$ carbo

Percent Composition and Stoichiometry

In an environmental analysis, a compound is found in a mineral with a mass composition of 40% metal

Photoelectron Spectroscopy Data Interpretation

The attached graph represents a simplified photoelectron spectrum for an element, showing distinct p

Reaction Equilibrium in Water Ionization

Water undergoes autoionization according to the equation: \(2*H_2O \rightleftharpoons H_3O^+ + OH^-\

Reaction Rate Dependence on Molarity: A Kinetic Study

The rate of a reaction often depends on the molarity of the reactants. Design an experiment to inves

Stoichiometry and Percent Yield Calculation

An experiment is conducted where aluminum reacts with chlorine gas to form aluminum chloride accordi

Understanding the Bohr Model and Energy Absorption

This question examines the application of the Bohr model to determine energy differences between ele

Valence Electrons and Periodic Trends

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

Advanced Lewis Dot Structures and Geometry of Phosphorus Pentachloride

Phosphorus pentachloride (PCl5) involves interesting bonding features including resonance and an exp

Analyzing Conductivity Across Bond Types

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

Bond Order Determination in Ozone

Ozone ($$O_{3}$$) exhibits resonance which affects its bond order. Answer the following:

Bonding Type and Solubility

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

Calorimetry for Bond Energy Determination

A student uses bomb calorimetry to measure the energy released during the combustion of methane ($$C

Comparative Electrical Conductivity of Various Compounds

A laboratory study investigates the electrical conductivity of various pure substances and their sol

Delineating Sigma and Pi Bond Contributions in Double Bonds

A double bond consists of one sigma bond and one pi bond, each contributing differently to the overa

Designing an Experiment on Ion Mobility in Solutions

Design an experiment to investigate the factors influencing the mobility of ions in an aqueous solut

Experimental Claims on Alloy Conductivity

A media report suggests that introducing a minor percentage of a secondary metal into a primary meta

Exploring Expanded Octets and Their Applications

This question focuses on the concept of expanded octets and asks you to both explain the phenomenon

FRQ20: Evaluating Orbital Hybridization in Bond Formation

Orbital hybridization plays a crucial role in determining both the bonding and geometry of molecules

Influence of Ionic Radius on Lattice Energy

Consider two ionic compounds with similar ionic charges but different ionic radii. Answer the follow

Infrared Spectroscopy and Bond Order Determination

A researcher uses infrared (IR) spectroscopy to study a series of diatomic molecules with the goal o

Investigating Bond Energy and Reaction Kinetics in Ionic Compounds

This question examines the relationship between ionic bond energy and reaction kinetics, using disso

Ionic Bond Strength Comparison

A materials scientist is investigating the factors that affect the lattice energy of ionic compounds

Lewis Acid-Base Reaction Conductivity Misinterpretation

To explore the behavior of Lewis acid-base reactions, a student dissolves a known Lewis acid in wate

Metallic Bonding and Electrical Properties

A researcher publishes a claim that all metals, due to their 'sea of electrons,' exhibit maximum ele

Network Covalent Bonding and Material Properties

Network covalent solids such as diamond and quartz have unique physical properties resulting from th

Network Covalent Solids and Bonding Strengths

Network covalent solids, such as diamond and quartz, are known for their high melting points and har

Quantitative Analysis of Bond Energy from Graph Data

Using a potential energy graph for a diatomic molecule, analyze the bond energy quantitatively.

Solubility and Conductivity Comparison Misinterpretation

A student compares the electrical conductivity of aqueous solutions of sodium chloride (an ionic com

The Role of Lone Pairs in Determining Bond Angles

A researcher examines the deviations in bond angles caused by lone pair repulsion by comparing water

Analysis of Contact Angle Measurements and Intermolecular Forces

A student performs an experiment to study how intermolecular forces influence the behavior of liquid

Beer’s Law and Concentration Measurement

A solution containing a colored compound is analyzed using a spectrophotometer. The measured absorba

Charles' Law and Volume Change with Temperature

The combined gas law explains how gas volume changes with temperature. Use Charles' law for a calcul

Chromatography: Separation of Mixed Pigments

In this question, you will use paper chromatography data to analyze pigment separation based on pola

Comparative Study of Intermolecular Forces in Organic Molecules

Using the provided experimental data, analyze the relationship among dipole moment, molar mass, and

Deviations from Ideal Gas Behavior

A researcher studies the behavior of a gas under high-pressure conditions where deviations from idea

Deviations from Ideal Gas Behavior at High Pressures

Using the experimental graph provided, analyze how real gases deviate from Ideal Gas Law predictions

Electromagnetic Spectrum and Electron Transitions

A researcher is investigating how molecules interact with electromagnetic radiation during electroni

Energy–Frequency Relationship in Light Absorption

An electron in a molecule absorbs a photon, resulting in a transition to a higher energy level.

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 Mixtures, Reaction Rates, and Kinetic Theory

During a combustion reaction, the reaction rate is influenced by the kinetic energy of gas molecules

Gas Pressure and Temperature Relationship

Consider a sealed container of gas in which the temperature is gradually increased. Based on kinetic

Gas Speed Comparison via Maxwell–Boltzmann Distribution

Examine differences in molecular speeds using the Maxwell–Boltzmann framework, and compute speeds us

Intermolecular Forces and Phase Changes

Examine the influence of intermolecular forces on phase changes by analyzing experimental boiling po

Intermolecular Forces and Phase Transitions Analysis

A claim has been made that substances with stronger intermolecular forces (IMFs) have higher boiling

Intermolecular Forces and Vapor Pressure: A Multi-Phase Analysis

A researcher is examining how differences in intermolecular forces affect the vapor pressure of liqu

Investigation of Gas Effusion Rates

A student designs an experiment to compare the effusion rates of two gases by using a container with

Maxwell–Boltzmann Diagram Interpretation and Temperature Effects

A Maxwell–Boltzmann diagram shows the distribution of molecular speeds at two different temperatures

Microwave Radiation and Molecular Vibrations

A researcher explores the interaction between microwave radiation and polar molecules to induce vibr

Non-Ideal Gas Behavior Analysis

Compare experimental gas pressures with predictions from the ideal gas law and explain the factors c

Paper Chromatography and Polarity Separation

Paper chromatography separates mixtures based on differences in solute-solvent interactions and pola

Paper Chromatography and Retention Factor Analysis

Paper chromatography separates a mixture based on differences in polarity. Analyze the separation us

Phase Changes and Bond Energy Considerations

A chemist is investigating the energy requirements for phase transitions in substances characterized

Photon Energy and the Electromagnetic Spectrum

Light absorption and emission are key to understanding electronic transitions in atoms. Analyze the

Quantitative Analysis Using Beer’s Law for Concentration Determination

Utilize the provided absorbance data to explore the relationship between concentration and absorbanc

Vibrational Spectroscopy and Molecular Polarity

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

Acid-Base Reaction and Titration Analysis

A strong acid reacts with a strong base in a titration experiment. Consider the reaction between hyd

Analyzing Redox Titration using KMnO4

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

Balancing Complex Chemical Equations and Reaction Mechanism Analysis

Ammonium dichromate decomposes according to the reaction: $$ (NH_4)_2Cr_2O_7 \rightarrow Cr_2O_3 + N

Balancing Redox Half-Reactions

Consider the redox reaction: $$Fe + 2 HCl \rightarrow FeCl_{2} + H_{2}$$. Analyze the oxidation-redu

Balancing Redox Reactions in Basic Solutions

In a basic solution, iodide ions (I−) are oxidized to iodine (I2). Answer the following: (a) Write

Buffer Solutions and pH Stability

A buffer solution is prepared by mixing equal concentrations (0.250 M) of acetic acid (HC2H3O2) and

Chemical Equilibrium: Le Chatelier’s Principle

For the equilibrium reaction $$N_2 (g) + 3*H_2 (g) \rightleftharpoons 2*NH_3 (g)$$, analyze the syst

Combustion Analysis of Hydrocarbons

Butane (C4H10) combusts in oxygen to produce carbon dioxide and water. In one experiment, 44.0 g of

Combustion Analysis: Determining Empirical Formula of a Hydrocarbon

A 1.00 g sample of a hydrocarbon is combusted, producing 3.30 g of \(CO_2\) and 1.35 g of \(H_2O\).

Comparative Analysis of Reaction Types

A researcher investigates several reaction types including synthesis, decomposition, redox, and prec

Determination of Unknown Concentration via Redox Titration

A redox titration is performed in which a known concentration of potassium permanganate (KMnO₄) solu

Determining the Limiting Reactant in a Redox Reaction

In redox reactions, the limiting reactant dictates the reaction’s extent. Design an experiment using

Effect of Reactant Purity on Precipitate Yield

Impurities in reactants can significantly affect the outcome of a precipitation reaction. Design an

Error Analysis in Balancing Chemical Equations

A student incorrectly balanced the equation $$Fe + O_2 \rightarrow Fe_2O_3$$.

Experimental Analysis of Percent Error in Chemical Reactions

In an experiment, the theoretical yield of a reaction product is 25.0 g while the experimental yield

FRQ 18: Electrochemical Cell and Electrode Potentials

A galvanic cell is constructed using a $$Zn/Zn^{2+}$$ half-cell and a $$Cu/Cu^{2+}$$ half-cell, with

FRQ 20: Calorimetry and Reaction Enthalpy Analysis

A calorimetry experiment is performed to determine the reaction enthalpy. The expected enthalpy chan

Gravimetric Analysis of Alkali Hydroxide Precipitation

A student dissolves a 4.33 g sample of an unknown alkali hydroxide in water. They add an excess of c

Gravimetric Analysis: Error Assessment in Precipitation Reaction

A series of trials in a gravimetric analysis experiment produced a precipitate whose measured masses

Gravimetric Analysis: Identification of a Metal Ion via Precipitation

An unknown solution containing a trivalent metal ion \(M^{3+}\) is treated with a base to precipitat

Industrial Ammonia Synthesis via the Haber Process

The Haber process synthesizes ammonia from nitrogen and hydrogen according to the reaction: $$N_2 +

Limiting Reactant and Stoichiometry in a Synthesis Reaction

In a synthesis reaction, 100.0 g of reactant A reacts with 150.0 g of reactant B to form compound AB

Limiting Reactant Determination in Hydrocarbon Combustion

Butane (C₄H₁₀) undergoes complete combustion according to the equation: $$2*C_4H_{10} + 13*O_2 \rig

Oxidation States Determination in Complex Ions

Examine the polyatomic ion sulfate ($$SO_4^{2-}$$) and the following reaction: $$Fe_2(SO_4)_3 + 6 H_

Precipitation Reaction and Gravimetric Analysis

Gravimetric analysis is a reliable method for quantitative determination through precipitation. Desi

Quantitative Analysis of a Precipitation Reaction

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

Reaction Rate Analysis through Graphical Data Interpretation

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

Redox Reaction Analysis: Iron and Hydrochloric Acid

Consider the reaction: $$Fe + 2\,HCl \rightarrow FeCl_2 + H_2$$. Answer the following:

Redox Titration: Determination of Iron(II) Concentration

A student performs a redox titration to determine the concentration of an iron(II) sulfate solution

Thermodynamic Analysis of Reaction Energetics

A researcher analyzes an exothermic reaction by examining its enthalpy and entropy changes to determ

Thermodynamic Calculations: Gibbs Free Energy Change

For a given reaction, the enthalpy change is $$\Delta H = -150.0\ kJ/mol$$ and the entropy change is

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 Competing Reaction Pathways

A reaction can proceed via two parallel pathways. Pathway 1 is first order with respect to reactant

Analysis of Second-Order Rate Law from Graphical Data

For a second-order reaction involving reactant A, the integrated rate law is given by $$\frac{1}{[A]

Analysis of Zero, First, and Second Order Reaction Kinetics

A student is provided with a summary table that compares three different kinetic analyses for a sing

Analyzing Reaction Mechanisms and Intermediates

Consider the following proposed mechanism for the reaction: Step I (fast): A + A → X Step II (slow)

Application of the Steady-State Approximation in Kinetic Analysis

Consider a reaction mechanism where an intermediate Z is formed in the first step and consumed in th

Arrhenius Equation and Temperature Dependence

A reaction’s rate constant k was determined at various temperatures. The following data was obtained

Arrhenius Equation and Temperature Effects

The rate constant $$k$$ of a reaction depends on temperature according to the Arrhenius equation: $$

Arrhenius Plot Interpretation

A series of experiments were conducted to determine the temperature dependence of a reaction rate. T

Computer Simulation in Kinetic Studies

A computer simulation of a chemical reaction provides concentration vs. time curves for the reaction

Determination of Rate Law from a Multi-Step Mechanism

Consider the following proposed reaction mechanism: Step I (fast): $$\text{A} + \text{B} \rightarro

Determining Rate Constant from Half-Life Data for a First-Order Reaction

A first-order reaction has a constant half-life throughout its progress. For a particular reaction,

Determining Rate Law from Reaction Mechanisms

A reaction proceeds through multiple steps. The proposed mechanism is as follows: I. A + A ⇌ X (fas

Determining Reaction Order from Continuous Monitoring Data

In a kinetic study, the concentration of reactant A was continuously monitored and recorded at vario

Determining Reaction Order from Time-Dependent Data

In an experiment, the concentration of reactant A was measured over time, yielding the following dat

Differentiating Reaction Order Using Half-Life Measurements

A series of experiments measured the half-life of a reactant at different initial concentrations. Us

Effect of Surface Area on Reaction Kinetics in Solid-Liquid Reactions

The rate of reaction between a solid and a liquid is often influenced by the surface area of the sol

Effects of Reactant Order on Reaction Kinetics

A series of experiments were conducted to analyze how the concentration of reactants influences the

Graphical Determination of Reaction Order

Different integrated rate law plots can be used to determine the reaction order. Answer the followin

Half-Life in First-Order Reactions

A first-order reaction has a half-life of 40 seconds. If a sample initially contains 0.50 M of react

Identification of the Rate-Determining Step

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

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

Integrated Rate Law Analysis for a Second-Order Reaction

A reaction is believed to follow second-order kinetics with respect to reactant A. The progress of t

Intermediate Detection in Reaction Mechanism: Measurement Error Analysis

An experiment was conducted to test a proposed two-step reaction mechanism for the conversion of $$A

Interpreting Reaction Energy Profiles

A reaction energy profile diagram is provided below. The diagram shows the energy of the reactants a

Investigating Reaction Mechanisms by Detecting Intermediates

In a reaction suspected to involve a short-lived intermediate, a researcher uses a radical scavenger

Kinetic Modeling of Chain Reactions in Polymerization

In a free radical polymerization, the following steps are proposed: Initiation: I → 2R• (rate cons

Mechanistic Insight from Induction Period Data

A reaction's rate versus time graph (provided in the stimulus) displays an induction period before t

Multi-Step Reaction Mechanism Analysis: Misidentification of the Rate-Determining Step

An experimental study was conducted to analyze a reaction mechanism with multiple steps. The propose

Proposing a Reaction Mechanism

Propose a detailed mechanism for the reaction $$A + 2*B \rightarrow D$$ that is consistent with the

Rate Constant Determination Using Stopped-Flow Data

A stopped-flow experiment is conducted to study the kinetics of a reaction under first-order conditi

Reaction Inhibition and Kinetic Analysis

In the unimolecular reaction $$A \to B$$, the addition of an inhibitor I is found to decrease the re

Role of Surface Area in Heterogeneous Reaction Rates

A heterogeneous reaction involving a solid reactant was performed using two different forms of the s

Temperature Effects on Reaction Rate: An Arrhenius Analysis

A gas-phase reaction was studied at various temperatures. The following data was collected: | Tempe

Zero-Order Reaction Kinetics Analysis

A reaction is suspected to follow zero-order kinetics. The concentration of reactant A was measured

Activation Energy and Reaction Mechanisms: Catalyst Effects

In an experiment, a catalyst is introduced to a reaction, and the energy diagram provided shows a lo

Application of Hess’s Law

A reaction can be carried out in a series of steps. Consider the following steps: Step 1: $$A \righ

Bond Energy Calculation via Combustion Reaction

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

Bond Energy Calculations for Reaction Enthalpy

A chemist is estimating the enthalpy change for the reaction: $$\text{H}_2 (g) + \text{Cl}_2 (g) \ri

Calorimetry Experiment with a Coffee Cup Calorimeter

A student conducts an experiment to measure the enthalpy change of an acid‐base neutralization react

Calorimetry: Determining Specific Heat

Calorimetry is used to determine the specific heat capacity of an unknown metal in an experimental s

Catalysis and Energy Diagrams Comparison

Evaluate the impact of a catalyst on the energy diagram of a chemical reaction using the provided di

Comparing Exothermic and Endothermic Reaction Energy Profiles

Two energy diagrams are provided side-by-side: one represents an exothermic reaction and the other a

Comparing Specific Heat Capacities of Different Substances

A study measures the specific heat capacities of three substances with the following data: | Substa

Comparing Theoretical and Experimental Enthalpy Changes

A reaction was studied using both theoretical bond energy calculations and experimental calorimetry.

Designing a Calorimetry Experiment

A researcher aims to measure the heat of reaction using a calorimeter.

Designing a Calorimetry Experiment to Measure Enthalpy of Fusion

Develop an experimental procedure to accurately measure the enthalpy of fusion for an unknown substa

Designing a Multi-Step Experiment to Determine Reaction Enthalpy

Design a laboratory experiment to determine the enthalpy change $$\Delta H$$ for a reaction that occ

Determining Enthalpy of Fusion of Ice

A student attempts to determine the enthalpy of fusion of ice using a simple calorimetry experiment.

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 Profiles of Reversible Reactions

Analyze the energy diagram for a reversible reaction provided in the stimulus. The diagram shows bot

Environmental Impact of Endothermic Processes

Endothermic reactions absorb energy from their surroundings and can impact the environmental energy

Evaluating Experimental Design in Calorimetry

A research group designed an experiment to measure the enthalpy change of a neutralization reaction

Frictional Heating and Energy Conversion

In a friction experiment, a block slows down as it slides along a surface and its temperature increa

Interpreting a Phase Change Calorimetry Graph

Examine the attached graph showing temperature versus heat added for a substance undergoing a phase

Investigating Endothermic Reaction Mechanisms

Endothermic reactions absorb energy, resulting in distinct energy profiles compared to exothermic re

Reaction Enthalpy and Energy Diagrams

A chemical reaction is performed which is known to be exothermic with a reaction enthalpy of $$\Delt

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

Thermodynamics of Sublimation

Consider a substance with an enthalpy of sublimation given by $$ΔH_{sub} = 30.0\ kJ/mol$$. Answer th

Acid-Base Equilibria: Ka Calculation

For the weak acid HA undergoing dissociation: $$HA (aq) \rightleftharpoons H^{+} (aq) + A^{-} (aq)$$

Application of Reaction Quotient (Q) in Determining Equilibrium Shift

For the reaction $$SO_2 + H_2O \leftrightharpoons H_2SO_3$$, answer the following parts.

Application of the Reaction Quotient (Q) in Process Monitoring

In an industrial process, it is important to continually monitor the reaction state. The reaction qu

Calculating Keq for the Haber Process

In the Haber Process, the production of ammonia is governed by the reaction $$\text{N}_2 + 3*\text{H

Calculating Reaction Quotient from Experimental Data

In an experiment for the reaction $$\rm H_{2}(g) + I_{2}(g) \rightleftharpoons 2HI(g)$$, a student o

Catalysts and Reaction Equilibrium

A reversible reaction is monitored over time by measuring the concentration of product X. Two experi

Constructing and Using an ICE Table for Equilibrium Calculations

Use an ICE table to determine the equilibrium concentration of a weak acid in aqueous solution.

Data Analysis of Equilibrium via Graphical Representation

A researcher monitored the concentration of a reactant R over time for the reaction $$\text{R} \left

Determining Acid Dissociation Constant (Ka)

For the weak acid HA, which dissociates in water according to $$HA + H_2O \leftrightarrow A^- + H_3O

Determining the Solubility Product of AgCl

A researcher investigates the solubility of silver chloride (AgCl) in water. AgCl dissolves accordin

Dilution Effects on Aqueous Equilibrium

Examine the equilibrium reaction: $$Fe^{3+}(aq) + SCN^{-}(aq) \leftrightarrow FeSCN^{2+}(aq)$$.

Dilution Effects on Aqueous Equilibrium

A student investigated the equilibrium $$\text{Fe}^{3+} (aq) + \text{SCN}^- (aq) \rightleftharpoons

Dilution Effects on Aqueous Equilibrium Systems

Design an experiment to study the effect of small changes in volume (dilution or evaporation) on the

Dilution Impact on Aqueous Equilibrium

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

Dynamic Analysis of Reaction Progress to Equilibrium

A reaction $$\mathrm{X (aq) + Y (aq) \rightleftharpoons Z (aq)}$$ is monitored over time. The follow

Effect of Inert Gas Addition on Gaseous Equilibrium

Consider the gaseous equilibrium: $$D(g) + E(g) \rightleftharpoons F(g) + G(g)$$. The system is init

Effect of Temperature on Equilibrium Constant

A researcher studies an exothermic reaction with $$\Delta H = -92.6\;kJ/mol$$. The experiments measu

Equilibrium Analysis in a Biochemical System

In an enzyme-catalyzed reaction, the enzyme E facilitates the reversible conversion: $$S + E \rightl

Equilibrium in Salt Solubility Calculations

For the dissolution of PbCl₂, represented by: $$PbCl₂(s) \rightleftharpoons Pb²⁺(aq) + 2Cl⁻(aq)$$, t

Experimental Design: Determining Ksp of a Sparingly Soluble Salt

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

Exploring Equilibrium Expressions

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

Graph Analysis of Equilibrium Attainment

A graph depicting the concentration of reactants and products over time for a reversible reaction is

Haber Process Equilibrium Measurement Error

In a controlled experiment investigating the equilibrium constant for the Haber process, a chemist f

Hess's Law and Equilibrium Constant Combination: Error Identification

A researcher seeks to determine the overall equilibrium constant for a composite reaction by combini

Impact of External Inert Gas Addition on Equilibria

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

Interconversion of Kc and Kp in Gaseous Reactions

For a gaseous equilibrium reaction, the equilibrium constant can be expressed in terms of concentrat

Investigating the Reaction Quotient (Q)

Consider the reaction $$2*A + B \leftrightarrow 3*C + D$$. Using the initial concentrations provided

Kp and Kc Interconversion

For the reaction: $$N_2 (g) + 3*H_2 (g) \rightleftharpoons 2*NH_3 (g)$$, answer the following parts:

Linking Reaction Kinetics and Equilibrium

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

Manipulating Equilibrium Constants Through Hess's Law

Hess’s Law allows us to manipulate equilibrium constants when combining reactions. Consider the foll

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

Oxygen Binding in Hemoglobin: An Equilibrium Perspective

Hemoglobin binds oxygen reversibly, and its binding equilibrium can be influenced by changes in carb

PbCl2 Solubility and Stoichiometry Error in Common Ion Studies

A researcher studies the solubility of PbCl2 by dissolving a known mass in water and measuring the c

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

Reaction Mechanism and Equilibrium Shift Analysis

A complex chemical reaction proceeds via a two-step mechanism, with the first step achieving a rapid

Reaction Quotient and Precipitation Prediction

For the precipitation reaction $$CaF_2(s) \leftrightarrow Ca^{2+}(aq) + 2F^-(aq)$$ with $$K_{sp} = 3

Solubility Product and Precipitation Prediction

For the dissolution reaction of lead(II) chloride: $$\mathrm{PbCl_{2} (s) \rightleftharpoons Pb^{2+}

Solubility Product and the Common Ion Effect

The salt $$AB_2$$ dissolves in water according to the reaction: $$AB_2(s) \rightleftharpoons A^{2+}(

Solubility Product and the Common Ion Effect

Discuss the solubility product constant (Ksp) and the common ion effect in the context of a sparingl

Solubility Product Constant Calculations

For the dissolution of calcium fluoride, represented by $$CaF_2(s) \leftrightarrow Ca^{2+}(aq) + 2*F

Temperature Effects in an Exothermic Equilibrium

For the exothermic reaction Y ⇌ Z + energy, experiments were conducted at various temperatures. The

Temperature Effects on Equilibrium

Investigate how temperature variations influence both the equilibrium position and the equilibrium c

Temperature Effects on Equilibrium: Exothermic Reactions

The industrial Haber process for ammonia synthesis is exothermic with $$\Delta H = -92.6\;\text{kJ/m

The Common Ion Effect on Salt Solubility

Calcium fluoride dissolves according to $$CaF_2(s) \leftrightarrow Ca^{2+}(aq) + 2F^-(aq)$$ with $$K

Using a Graph to Extract Equilibrium Data

A reversible reaction is monitored over time with product concentrations recorded. Answer the follow

Acid Strength and Molecular Structure

Organic acids such as acetic acid and benzoic acid exhibit different acid strengths due to differenc

Analysis of pH versus pKa Graph in Buffer Systems

A graph plotting pH against $$\log\left(\frac{[A^-]}{[HA]}\right)$$ for a buffer system is provided.

Buffer Capacity and Dilution Effects

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

Buffer Capacity Experiment in River Water

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

Buffer pH Calculation

A buffer solution is prepared by mixing 0.20 M acetic acid (HC2H3O2) with 0.15 M sodium acetate (NaC

Buffer System Analysis using Henderson-Hasselbalch Equation

This question requires the analysis of a buffer system using the Henderson-Hasselbalch equation.

Designing a Buffer Solution

You are tasked with preparing a buffer solution with a target pH of 5.0 using a weak acid that has a

Determining pH in Acid Solutions

In an aqueous solution of a strong acid, the pH is determined by the concentration of hydrogen ions

Effect of Acid Concentration on Percent Dissociation of a Weak Acid

The percent dissociation of a weak acid is influenced by its concentration. Consider this concept in

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

Mixing Strong and Weak Acid Solutions

A chemist mixes 50.0 mL of 0.10 M HCl (a strong acid) with 50.0 mL of 0.10 M acetic acid (a weak aci

Neutralization Reaction and Titration Curve Analysis

Neutralization reactions, such as those between strong acids and strong bases, result in the formati

Percent Dissociation of a Weak Acid

This FRQ explores how the percent dissociation of a weak acid changes with concentration using exper

Polyprotic Acid Titration Analysis

Phosphoric acid ($$H_3PO_4$$) is a polyprotic acid with three dissociation steps. Its dissociation c

Polyprotic Acid Titration and Stepwise Dissociation

Phosphoric acid (H3PO4) is a polyprotic acid that dissociates in three steps with the dissociation c

Quantitative pH Analysis with Percent Dissociation: Calculation Error

A student investigated the percent dissociation of acetic acid in a dilute aqueous solution by measu

Solubility of Mg(OH)₂ in High pH Environments: Conceptual Misinterpretation

A student conducted an experiment to study the solubility of Mg(OH)₂ by adding it to two different s

Titration Lab Analysis of a Polyprotic Acid

A laboratory experiment involves titrating a polyprotic acid with a strong base. The resulting titra

Titration of a Polyprotic Acid (H₃PO₄)

This problem involves titrating phosphoric acid (a polyprotic acid) and understanding the significan

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

Analyzing a Voltaic Cell's Performance Over Time

A report claims that the voltage output of a voltaic cell remains constant over several hours of ope

Analyzing Gibbs Free Energy with Reaction Quotient

Consider the redox half-reaction: $$Fe^{3+} + e^- -> Fe^{2+}$$ with a standard reduction potential o

Calorimetry Misapplication in Thermodynamic Measurements

In an attempt to determine both the enthalpy (\(\Delta H^\circ\)) and entropy (\(\Delta S^\circ\)) c

Comparing Spontaneity in Redox vs. Non-redox Reactions

A complex chemical process involves coupling a spontaneous redox reaction with a non-spontaneous rea

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 Experiment

A recent report claims that a novel salt bridge design in a galvanic cell results in higher voltage

Designing a Multi-step Redox Reaction Experiment

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

Electrolytic Cell and Electroplating Calculations

An electroplating process via an electrolytic cell is reported to deposit a metal coating by passing

Electroplating Efficiency and Calculations

Electroplating is a common industrial application of electrolytic cells. Analyze the process with th

Entropy and the Second Law Critique

A popular science article states that the Second Law of Thermodynamics implies that all processes in

Entropy Change Analysis

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

Entropy Changes in Phase Transitions

The table below lists various phase transitions along with their respective entropy changes (ΔS). An

FRQ 11: Relating Equilibrium Constants to Cell Potentials

A certain redox reaction in a galvanic cell involves an exchange of \(n = 3\) electrons and has a st

Gibbs Free Energy and n-Faraday Relationship

A redox reaction involves the transfer of 3 moles of electrons and has a measured cell voltage of 1.

Gibbs Free Energy and Reaction Favorability

The table below summarizes data for four different reactions, including their standard enthalpy (ΔH

Gibbs Free Energy Correction Under Non-Standard Conditions

A redox reaction is observed under non-standard conditions and its cell potential is lower than the

Graph Analysis: Determining Enthalpy Change

A graph depicting a linear relationship between \(\ln K\) and \(1/T\) has been obtained from experim

Interpreting the Relationship Among ∆H, ∆S, and ∆G

A reaction is carried out under two sets of conditions at 298 K: Case 1: $$\Delta H^\circ = -100\,kJ

Investigating the Effect of Pressure on Reaction Entropy

Design an experiment to measure the impact of pressure on the entropy change of a gas-phase reaction

Kinetics vs Thermodynamics in Electrochemical Cells

A study claims that the rate of an electrolysis process is determined solely by its thermodynamic fa

Predicting the Effect of Temperature on Reaction Spontaneity

A reaction has a standard enthalpy change of $$+80\,kJ/mol$$ and a standard entropy change of $$+250

Thermodynamic Favorability: Interplay of $$\Delta H$$ and $$\Delta S$$

Examine the following reaction data and use it to analyze thermodynamic favorability from the relati