AP Chemistry FRQ Room

Application of the Aufbau Principle in Determining Electron Configurations

Determine the electron configuration for phosphorus (atomic number 15) and explain the principles gu

Application of the Aufbau Principle in Electron Configuration

Determine an element's electron configuration using the Aufbau principle and discuss its limitations

Covalent Compound Composition Analysis with Misleading Percent Data

A researcher attempts to determine the percent composition of a novel covalent compound by combustin

Designing an Experiment: Determining Molar Mass from Gas Density

An unknown gas is collected at STP. The measured mass of the gas is $$2.24$$ g and it occupies a vol

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 and Periodic Trends

Sulfur (atomic number 16) has electrons that fill various orbitals according to the Aufbau Principle

Empirical and Molecular Formula Determination

A compound is analyzed and found to consist of 56.5% carbon, 7.11% hydrogen, and 36.4% phosphorus by

Empirical Formula Determination from Percent Composition

An unknown compound is found to have a percent composition of 40.0% sulfur, 13.3% hydrogen, and 46.7

Interpreting Electron Configuration Diagrams

A diagram shows the electron configuration for Element X as follows: $$1s^2, 2s^2, 2p^6, 3s^2, 3p^4$

Ionization Energy Trends and Electron Shell Structure

Discuss the trends in ionization energy based on electron configuration and atomic structure.

Isotopic Abundance Analysis for Carbon

An experiment was conducted to measure the isotopic composition of carbon. The data collected show t

Mass Spectrometry and Isotopic Abundance

A mass spectrum of selenium shows five naturally occurring isotopes. Consider the following simplifi

Mole Calculations in Chemical Reactions

In a laboratory experiment, a chemist measures a 24.022 g sample of carbon and uses it in a combusti

Periodic Trends and Electron Shielding

A researcher examines periodic trends, focusing on elements in period 2, to better understand atomic

Photoelectron Spectroscopy Analysis

A photoelectron spectrum (PES) provides information on the binding energies of electrons in various

Reaction Equilibrium in Water Ionization

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

Selenium Mass Spectrometry Analysis

Analyze a mass spectrometry data set for selenium to determine key isotopic information and assess m

Valence Electrons and Chemical Reactivity: A Comparative Study

This question compares chemical reactivity between elements by analyzing their electron configuratio

Alloy Formation: Interstitial vs. Substitutional Alloys

Metal alloys exhibit properties that differ from their constituent metals. Compare and contrast inte

Bond Energetics: Reaction Energy Analysis

Analyze a reaction based on bond dissociation and formation energies to determine the net energy cha

Bond Energy and Internuclear Distance in Covalent Bonds

This question examines the relationship between bond energy and internuclear distance in covalent bo

Bond Strength Analysis in Ionic and Metallic Compounds

A media report claims that, based solely on Coulomb’s Law, ionic compounds with higher ionic charges

Catalysis in Covalent Bond Formation Kinetics

A student investigates the role of a catalyst in a covalent bond-forming reaction by conducting para

Expanded Octets in Main Group Elements

Some main group elements can form expanded octets by utilizing available d orbitals. Explore this ph

Formal Charge and Resonance Stability in Nitrate Ion

This question requires you to define formal charge, calculate it, and use it to compare the stabilit

Formal Charge Distribution in Sulfur Trioxide (SO₃)

The stable configuration of molecules can often be predicted by formal charge calculations. Examine

Formal Charge Misinterpretation via Titration Experiment

A student attempts to determine the formal charge distribution in a polyatomic ion by performing an

FRQ5: Comparing Network Covalent Structures – Diamond vs. Graphite

Diamond and graphite are both forms of carbon with network covalent bonding, yet they have vastly di

Ionic Bond Lattice Energy Analysis

This question focuses on analyzing ionic bond energy trends using provided compound data.

Ionic Lattice Energy Comparison

Consider several ionic compounds such as NaCl, MgO, and Al2O3. Each compound is composed of ions wit

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

Kinetic Analysis in Gas-Phase Reactions with Collisional Theory Error

A researcher examines the kinetics of a gas-phase reaction involving a covalent molecule by measurin

Measuring Bond Strength via Differential Scanning Calorimetry (DSC)

A research group employs differential scanning calorimetry (DSC) to determine the bond dissociation

Metallic Bonding and Alloy Formation

A materials scientist is investigating the properties of alloys. Two types of alloys are studied: an

Metallic Bonding and Electrical Conductivity

Metallic bonding involves a "sea of electrons" that contributes to electrical conductivity. Refer to

Periodicity in Bonding Trends

A chemist investigates how atomic properties across a period affect the nature, character, and energ

Resonance Structures and Molecular Stability

A researcher asserts that the presence of multiple resonance structures in a molecule leads to decre

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

Viscosity of Ionic Liquids and Ionic Concentration Assumption

A researcher synthesizes a novel ionic liquid and measures its viscosity using a viscometer to inves

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

Atomic Spectroscopy and Electron Transitions

An astrophysicist is analyzing light spectra from a distant star to determine its elemental composit

Chromatography and Polarity Separation

In a paper chromatography experiment, pigments are separated based on polarity. The following data w

Chromatography and Polarity Separation

A researcher employs paper chromatography to separate dyes from an ink sample. The movement of each

Comprehensive Analysis of Gaseous Systems

A researcher conducts a comprehensive study of a gaseous system by integrating kinetic molecular the

Distillation Experiment: Analyzing Boiling Points in Liquid Mixtures

A chemist is studying the separation of two miscible liquids with different boiling points using dis

Effusion and Molar Mass Calculation

A researcher determines the molar mass of an unknown gas by measuring its rate of effusion compared

Effusion Rate Experiment: Investigating Gas Separation

A student proposes an experiment to measure the effusion rate of two different gases through a very

Energy Transitions and the Electromagnetic Spectrum

Evaluate the relationship between wavelength and the type of energy transition in atoms using the pr

Evaluation of Hydrogen Bonding Effects Using Distillation

A student designs an experiment to evaluate the impact of hydrogen bonding on the boiling points of

Intermolecular Forces and Boiling Points

Intermolecular forces (IMFs) determine physical properties such as boiling points. Analyze the relat

Intermolecular Forces Ranking in Various Substances

This challenge requires you to analyze and rank several molecules based on the strength of their int

Investigation of Gas Effusion Rates in Micro-Perforated Containers

A student designs an experiment to study the effusion of a gas using a container with micro-perforat

Maxwell–Boltzmann Diagram Interpretation and Temperature Effects

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

Molecular Geometry and Polarity Exceptions

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

Solubility Analysis of Polar and Nonpolar Compounds

A student aims to compare the solubility of polar and nonpolar compounds by dissolving equal masses

Acid-Base Equilibria and Conjugate Pairs

A researcher investigates the equilibrium behavior of acetic acid in aqueous solution to understand

Acid-Base Reaction and Titration Analysis

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

Application of the Ideal Gas Law in Reaction Conditions

A reaction that produces a gaseous product is carried out in a sealed 10.0 L container at a temperat

Balancing and Stoichiometry in a Combustion Reaction

A combustion reaction involving a hydrocarbon is monitored by measuring the production of CO₂ over t

Balancing Chemical Equations and Percent Error Calculation

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

Balancing Redox Half-Reactions

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

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 Analysis of a Hydrocarbon

Combustion analysis can be used to determine the empirical formula of an unknown hydrocarbon. Design

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 \(H_2O\).

Combustion Reaction Analysis and Empirical Formula Determination

A hydrocarbon underwent complete combustion in a controlled experiment. The following table with com

Determination of Percent Error in Titration Experiments

In a titration experiment to determine the concentration of an unknown acid, a student compares the

Error Analysis in Balancing Chemical Equations

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

FRQ 7: Acid-Base Titration Curve Interpretation

During an acid-base titration of acetic acid with NaOH, it is claimed that the equivalence point is

Galvanic Cell and Redox Potential Calculations

A researcher investigates a galvanic cell constructed with zinc and copper electrodes. The half-cell

Hydrocarbon Combustion Analysis for Empirical Formula Determination

A 2.00 g sample of an unknown hydrocarbon is completely combusted in excess oxygen, resulting in the

Integrated Analysis of Water Treatment Process

A water treatment facility uses a multi-step process to remove iron contaminants from water. The pro

Investigation of Synthesis Reaction in Metal Alloys

A researcher investigates the synthesis reaction between two pure metals, Metal A and Metal B, to fo

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

Multi-Variable Effects on Reaction Kinetics

Reaction kinetics are often influenced by several factors at once. Design an experiment to study the

Oxidation-Reduction Reaction: Iron and Hydrochloric Acid

A student designs an experiment where iron metal reacts with hydrochloric acid to produce iron(II) c

Precipitation Reaction: Formation of Silver Chloride

Silver nitrate reacts with sodium chloride in aqueous solution to form silver chloride precipitate a

Reaction Kinetics in Decomposition of Hydrogen Peroxide

A laboratory experiment investigates the decomposition of hydrogen peroxide (\(H_2O_2\)) catalyzed b

Redox Titration Kinetics and Concentration Determination

In a redox titration experiment using $$KMnO_{4}$$, the progress of the titration is monitored by me

Synthesis and Decomposition Reaction Analysis

This FRQ examines the concepts of synthesis and decomposition reactions. Consider a scenario where r

Synthesis Reaction for a Complex Salt

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

Thermodynamics: Enthalpy Change in a Reaction

Consider the synthesis reaction: $$N_2 (g) + 3*H_2 (g) \rightarrow 2*NH_3 (g)$$. A calorimetry exper

Analysis of Reaction Mechanism in a Multi-Step Reaction

A reaction converting A + B to D is proposed to occur through the following mechanism: Step I (fast

Analyzing Reaction Mechanisms and Intermediates

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

Arrhenius Plot Analysis

Arrhenius plots are a common graphical tool used to determine activation energy. Answer the followin

Catalysts in Reaction Mechanisms

Consider the reaction A + B → C that occurs via the following mechanism: I. A + X → Y II. B + Y → C

Comparing Experimental and Theoretical Rate Laws

For a reaction, experimental kinetics yield a rate law of $$\text{Rate} = k [A]^2 [B]$$, while theor

Comparison of Experimental Techniques for Measuring Reaction Rates

A researcher uses two different methods to determine the rate constant of a reaction: spectrophotome

Correlation between Reaction Mechanism Steps and Experimental Rate Law

A reaction is proposed to proceed by two different mechanisms. One mechanism is a single-step, bimol

Determining Reaction Mechanisms from Isotope Labeling Experiments

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

Determining the Rate Constant for a First-Order Reaction Using Graphs

A first-order reaction is monitored by measuring the natural logarithm of the concentration of react

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 Temperature on Reaction Rate: Arrhenius Equation Application

Temperature can greatly influence reaction rates according to collision theory and the Arrhenius equ

Elucidating Reaction Mechanism and Rate-Determining Step

Consider the following elementary reaction mechanism: I. $$A + A \rightarrow X$$ (fast) II. $$X +

Enzyme Kinetics and Michaelis-Menten Analysis

Enzyme-catalyzed reactions often follow Michaelis-Menten kinetics. Answer the following:

Enzyme Kinetics and the Michaelis-Menten Equation

An enzyme catalyzes the conversion of substrate S to product P. The following experimental data for

Graphical Analysis of Second-Order Rate Law

A graph of 1/[A] versus time for a reaction is provided. This graph should be linear if the reaction

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

Homogeneous Reaction Rate and Stirring: Evaluating Conceptual Assumptions

In an experiment designed to study the reaction rate of a homogeneous reaction, the researcher alter

Integrated Rate Law Order Determination

Researchers studying the decomposition of substance A obtained the following data: | Time (min) | [

Investigating Half-Life in First-Order Reactions

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

Investigating the Effect of Pressure on Gas-Phase Reaction Rates

A chemist investigates the decomposition of a gaseous compound by varying its pressure while keeping

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 Analysis of Enzyme-Catalyzed Reactions

A biochemist studies an enzyme-catalyzed reaction following Michaelis-Menten kinetics. The initial r

Kinetic Isotope Effect Investigation

A reaction was performed using a reactant containing hydrogen (H) and then repeated with the deuteri

Kinetic Modeling of Chain Reactions in Polymerization

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

Kinetic Study of a Bimolecular Reaction (A + B → Products)

Design an experiment to determine the rate constant for the bimolecular reaction $$A + B \rightarrow

Mechanism Elucidation from Kinetic Data for a Reaction with Rate = k[A]^2[B]

Experimental data for a reaction suggest that the rate law is $$\text{Rate} = k[A]^2[B]$$. One propo

Multi-Reactant Order Determination

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

Photochemical Reaction Kinetics in a Light-Activated Reaction

Certain reactions are initiated by the absorption of light (photochemical reactions).

Pressure Effects on Gaseous Reaction Rates

A gas-phase reaction was studied at different pressures. The data below shows the observed reaction

Role of Catalysts in Reaction Mechanisms

Catalysts speed up chemical reactions without being consumed. Consider the following catalyzed react

The Effect of Temperature on Reaction Kinetics

A chemical reaction was studied at several temperatures. The following table lists the measured rate

Transient Intermediate Analysis via Spectrophotometry

In a reaction mechanism, a colored intermediate X is formed and then decays. A spectrophotometric st

Analysis of Reaction Mechanisms Through Bond Energy Considerations

Consider the combustion reaction: $$\text{C}_2\text{H}_6 + \text{O}_2 \rightarrow \text{CO}_2 + \tex

Analyzing Thermodynamic Data for Reaction Feasibility

A study claims that the measured enthalpy change (ΔH) of a reaction alone can predict its spontaneit

Calorimetry and Specific Heat Calculation

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

Calorimetry Experiment: Measuring Specific Heat of an Unknown Metal

You are provided with the following calorimetry data for an experiment in which an unknown metal is

Calorimetry of Enthalpy of Combustion with Radiation Loss

A student performs a combustion experiment using a simple calorimeter to measure the enthalpy of com

Catalysts and Activation Energy

Examine the energy profiles of a reaction with and without a catalyst. Answer the following question

Comparative Bond Energy Calculations

Consider two hypothetical reactions: Reaction 1: Breaking one C–H bond and forming one C–C bond. Rea

Comparing Exothermic and Endothermic Reaction Energy Profiles

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

Designing a Calorimetry Experiment

You are tasked with designing an experiment to determine the specific heat capacity of an unknown me

Designing an Experiment to Measure Bond Energies

Bond energies play a critical role in determining the enthalpy change of a reaction. Discuss how bon

Determination of Enthalpy of Formation (ΔHf)

A student carries out a multistep synthesis experiment to determine the enthalpy of formation (ΔHf)

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

Effect of a Catalyst on Reaction Energy Diagram

An energy diagram is provided for a chemical reaction conducted both with and without a catalyst. Th

Endothermic and Exothermic Reaction Identification

Given an energy diagram where the products have a lower energy than the reactants, answer the follow

Energy Diagram Analysis for Exothermic and Endothermic Reactions

A researcher provided energy diagrams for two reactions with different characteristics. The diagrams

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 Diagram Misinterpretation with Catalyst

A student uses infrared spectroscopy data to construct an energy diagram for an exothermic reaction.

Energy Diagrams and Catalysis

Examine the energy diagrams provided. This FRQ focuses on interpreting reaction coordinate diagrams

Energy Diagrams and Reaction Enthalpy

A researcher is studying a reaction's energy diagram for an exothermic process. The provided graph s

Energy Profiles of Reversible Reactions

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

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

Enthalpy of Formation and Reaction Stability

The standard enthalpies of formation ($$ΔH_f°$$) for compounds are provided in the following table:

Enthalpy of Formation Using Hess's Law

Consider the reaction for the formation of methanol: $$C(s) + \frac{1}{2}O_2(g) + 2H_2(g) \rightarro

Environmental Impact of Endothermic Processes

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

Experimental Investigation of Phase Change Thermodynamics

A researcher studies the melting of ice. Starting with 20.0 g of ice at -5°C, the substance is heate

Interpreting Calorimetry Data from a Metal-Water Reaction

In a calorimetry experiment, a heated metal is immersed in water, and the temperature of the water i

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

Investigating the Effect of Temperature on Reaction Rate in Catalyzed Reactions

This question explores the influence of temperature on the rate of a catalyzed chemical reaction. Th

Latent Heat and Energy Conservation in Phase Change: A Combined Analysis

A combined experiment involves both a temperature-time graph and a data table for a water sample und

Modeling the Heat Transfer in Industrial Processes

An industrial reactor designed for a chemical process experiences significant heat loss, affecting o

Role of Solvation in Enthalpy of Solution

An experiment examines the dissolution of various salts in water using calorimetry. One of the exper

Thermodynamic Analysis of Bond Formation and Breaking

A chemical reaction involves breaking bonds in the reactants and forming bonds in the products. If t

Using Hess’s Law with Experimental Data

Experiments have been conducted to determine the enthalpy changes for two intermediate reactions tha

Acid-Base Equilibria: Ka and Kb Definitions

Discuss the role of the acid dissociation constant (Ka) in weak acid equilibria and how it relates t

Acid-Base Equilibria: Ka and pH Calculation

Acetic acid (CH$_3$COOH) is a weak acid with an acid dissociation constant of $$K_a = 1.8 \times 10^

Calculation of the Reaction Quotient (Q)

For the reaction $$A + 2*B \rightleftharpoons 3*C$$, analyze the following concentration data provid

Catalysis and its Effect on Reaction Kinetics and Equilibrium

A study examined the effect of a catalyst on the reversible reaction $$X + Y \rightleftharpoons Z$$.

Combined Equilibrium Reactions and Keq Calculation

Consider the following two reversible reactions with their respective equilibrium constants: Reacti

Common Ion Effect Misconception in Solubility

A laboratory study examines the solubility of silver chloride (AgCl) by adding varying amounts of so

Common Ion Effect on Solubility of AgCl

Consider the dissolution of silver chloride according to the equation $$AgCl(s) \leftrightarrow Ag^+

Conversion between Kc and Kp

For the gaseous reaction $$\rm N_{2}(g) + 3H_{2}(g) \rightleftharpoons 2NH_{3}(g)$$, address the fol

Conversion from Kc to Kp in Gas-Phase Equilibria

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

Dilution Effects on Aqueous Equilibria

Investigate the impact of dilution on an aqueous equilibrium system.

Dilution Effects on Aqueous Equilibrium

For the equilibrium reaction $$Fe^{3+}(aq) + SCN^{-}(aq) \leftrightarrow FeSCN^{2+}(aq)$$, answer th

Dilution Effects on Aqueous Equilibrium

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

Effect of Dilution on Aqueous Equilibria

Investigate how dilution (adding water) affects the position of equilibrium in aqueous systems.

Effect of Inert Gases on Equilibrium Systems

Examine how the addition of an inert gas affects the equilibrium position of a gaseous reaction unde

Equilibrium Expression and Q Calculation

Consider the general equilibrium reaction: $$a*A + b*B \rightleftharpoons c*C + d*D$$. (a) Write the

Equilibrium in Multiphasic Systems

Consider a reaction involving both gaseous and aqueous species: $$X(g) + Y(aq) \leftrightarrow Z(aq)

Equilibrium in Salt Solubility Calculations

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

Examining the Role of Catalysts in Equilibrium

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

Experimental Design for Equilibrium Constant Measurement

You are tasked with designing an experiment to determine the equilibrium constant, $$K_{eq}$$, for t

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 the Common Ion Effect on Solubility

Design an experiment to investigate the effect of adding a common ion on the solubility of $$AgCl$$,

Graph Analysis: Reaction Equilibrium Data

Examine the provided graph which shows the change in concentration of a reactant over time as the sy

Graphical Interpretation of Concentration-Time Data in a Gas Reaction

The reaction $$\mathrm{A (g) + B (g) \rightleftharpoons C (g)}$$ was monitored, and the following gr

Hess’s Law and Constant Manipulation

Consider the following reactions: (a) $$M \rightleftharpoons N$$ with $$K_a = 2.5$$ (b) $$N \rightle

Hess's Law and Equilibrium Constant Manipulation

A chemist is analyzing how equilibrium constants change when individual reactions are manipulated. A

Impact of Dilution on an Aqueous Equilibrium

An equilibrium system involving aqueous ions is represented by the reaction: $$Fe^{3+}(aq) + SCN^{-}

Impact of the Common Ion Effect on Solubility

For the equilibrium $$\text{AgCl (s)} \rightleftharpoons \text{Ag}^+ (aq) + \text{Cl}^- (aq)$$, expe

Industrial Equilibrium: Reaction Shifts in the Synthesis of Sulfuric Acid

In the industrial process for producing sulfuric acid, the following reaction is considered to be in

Industrial Equilibrium: The Contact Process for Sulfuric Acid Production

Examine the Contact Process for sulfuric acid production represented by the reaction $$2*SO_2 (g) +

Influence of External Pressure on Gaseous Equilibria

Design an experiment to investigate the effect of external pressure changes on the equilibrium of th

Ionization of Water, Kw, and pH Changes

Consider the ionization of water, described by the equilibrium $$H_2O(l) \leftrightarrow H^+(aq) + O

Monitoring Equilibrium Progress Using the Reaction Quotient

A researcher is studying the reaction $$A + B \rightleftharpoons C + D$$ to understand how far the s

Multi-step Equilibrium Manipulations

Combine multiple reactions by manipulating their equilibrium expressions to derive an overall equili

Multiple Equilibria in Aqueous Systems

In an aqueous solution, two equilibria occur simultaneously: (1) $$C(aq) + D(aq) \rightleftharpoons

Pressure and Volume Effects in Gaseous Equilibria

Analyze the impact of changes in pressure and volume on the equilibrium position of a gaseous reacti

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, Volume, and Kinetics in a Gas Reaction

Consider the gaseous equilibrium reaction: $$P(g) + Q(g) \rightleftharpoons R(g)$$, which is initial

Quantitative Analysis of Reaction Quotient Q

In a study of the reaction $$X + Y \rightleftharpoons Z$$, initial concentrations are $$[X] = 0.6\,M

Quantitative Equilibrium Calculation in a Weak Acid System

A weak acid, HA, dissociates according to $$HA \leftrightarrow H^{+} + A^{-}$$. In a 1.0 L solution,

Quantitative Equilibrium Calculations: Molar Solubility

For the salt $$\rm CaF_{2}(s) \rightleftharpoons Ca^{2+}(aq) + 2F^{-}(aq)$$ with a given $$K_{sp} =

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 and Equilibrium Shifts

For the reversible reaction: $$D(g) + 2\,E(g) \rightleftharpoons F(g)$$, the reaction quotient $$Q$$

Relating Kp and Kc in a Gaseous Reaction

Consider the equilibrium reaction: $$PCl_5(g) \rightleftharpoons PCl_3(g) + Cl_2(g)$$. A chemist ana

Simultaneous Effects on Equilibrium

Consider the equilibrium reaction: $$2X(g) + Y(g) \rightleftharpoons 3Z(g)$$ A system at equilibrium

Solubility Product and Common Ion Effect: Error Analysis

A researcher studies the solubility of AgCl by preparing solutions in pure water and in water contai

Solubility Product Constant (Ksp) Calculation

Define and utilize the solubility product constant (Ksp) to predict the solubility of a sparingly so

Temperature and Reaction Energetics in Exothermic vs. Endothermic Reactions

Two reactions are studied under identical conditions. Reaction 1 is exothermic with $$\Delta H = -80

Temperature and Solubility

The following table provides the solubility of a salt in water at different temperatures: | Tempera

Temperature Effects on Equilibrium

Examine the effect of temperature on the equilibrium constant for an exothermic reaction such as the

Temperature Effects on Equilibrium Constants

Consider the exothermic reaction $$\mathrm{N_2 + 3H_2 \rightleftharpoons 2NH_3}$$ with $$\Delta H =

Uncertainty and Error Analysis in Equilibrium Studies

An experiment was conducted to measure the equilibrium concentrations for the reaction: $$G + H \rig

Analysis of Polyprotic Acid Titration

A titration experiment is conducted using phosphoric acid (H3PO4), a polyprotic acid, with a strong

Analyzing pH Changes during a Strong Acid-Strong Base Titration

A titration of 0.1 M HCl with 0.1 M NaOH is performed, and a graph of pH versus volume of NaOH added

Analyzing Titration Data with Equilibria Concepts

During the titration of a weak acid with a strong base, pH measurements are recorded. Analyze the ti

Application of pH in Environmental Chemistry: Acid Rain Effects

Acid rain forms when atmospheric pollutants mix with water, lowering the pH of lakes and other natur

Buffer Capacity and pH Stability

A buffer solution is prepared by mixing a weak acid and its conjugate base. Consider a buffer system

Buffer pH Calculation

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

Buffer Preparation Using a Conjugate Pair: Error in pKa Selection

A student attempted to design a buffer solution with a target pH of 9 using acetic acid and sodium a

Calculating pH Changes in a Buffer System Upon Addition of a Strong Acid

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

Common Ion Effect Misinterpretation in Solubility

An experiment was conducted to determine the solubility of Mg(OH)₂ by dissolving it in solutions of

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

Determination of pH in a Dilute Strong Acid Solution

This FRQ focuses on determining the pH of a dilute strong acid solution by comparing calculated and

Dilution Effects on Buffer Capacity

Buffer capacity is influenced by the concentration of buffering agents. Address the following:

Indicator Selection in Titration of Weak Acid with Weak Base

Titrations involving weak acids and weak bases may present ambiguous end points due to gradual pH ch

Indicator Transition Misinterpretation in Acid–Base Titration

During a titration of a weak acid with a strong base, a student chose phenolphthalein as the indicat

Kinetics in Acid–Base Neutralizations

A reaction between a strong acid (HCl) and a weak base (NH₃) is being studied. The reaction is assum

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

Modeling Titration Curves of a Polyprotic Acid

In a titration experiment with phosphoric acid (H3PO4), a triprotic acid, a student is asked to mode

Neutralization Reactions: Strong vs. Weak Bases

A series of experiments were conducted where a fixed volume of 0.1 M HCl was neutralized by either 0

Polyprotic Acid: Dilution Effects on Second Dissociation

Explore the effect of dilution on the second dissociation of sulfuric acid (H₂SO₄), which acts as a

Predicting pH Changes When Mixing a Strong Acid with a Buffer

This FRQ examines how the addition of a strong acid to a buffer solution affects the pH, using exper

Strong Acid-Strong Base Titration Analysis

In an experiment, 25.0 mL of 0.10 M HCl is titrated with 0.10 M NaOH. The pH is measured throughout

Strong Base pOH Calculation

A solution of a strong base has a hydroxide ion concentration of $$[OH^-] = 2.5 \times 10^{-3} \text

Weak Acid Percent Dissociation Analysis

Consider a 0.050 M acetic acid solution with a dissociation constant $$K_a = 1.8 \times 10^{-5}$$. T

Weak Base and Buffer System Analysis

Consider the buffer system formed by ammonia (NH3) in water. Answer the following:

Analyzing Galvanic Cell Performance with Electrode Error

A researcher built a galvanic cell using copper and zinc electrodes with 1.0 M electrolyte solutions

Catalysts and Free Energy

A catalyst is added to a reaction that has a standard free energy change of \(\Delta G^\circ = +25\,

Comparative Analysis of Redox Reactions

A researcher is provided with several redox half-reactions and their standard reduction potentials.

Comparing Galvanic and Electrolytic Cell Mechanisms

A media report suggests that the only difference between galvanic and electrolytic cells is the sign

Designing a Faraday’s Law Electroplating Experiment

In an electroplating experiment, a constant current is applied to deposit a metal on a cathode. Cons

Designing an Experiment to Measure Gibbs Free Energy Change using a Galvanic Cell

Design a controlled experiment to determine the standard Gibbs free energy change $$\Delta G^\circ$$

Determining $$\Delta G^\circ$$ from Equilibrium Constant Data

A chemist aimed to calculate the standard free energy change ($$\Delta G^\circ$$) for the reaction $

Determining Equilibrium Constant from Free Energy Data

The table below provides standard free energy changes (ΔG°) and the corresponding equilibrium consta

Electrochemical Analysis in Corrosion Prevention

A researcher investigates galvanic corrosion in a system involving two different metals. The standar

Electrochemical Cells: Galvanic Cell Analysis

A researcher builds a galvanic cell by combining two half-reactions and measures a standard cell pot

Electrolytic Cell and Electroplating Calculations

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

Entropy and Enthalpy in Reaction Series

Analyze the thermodynamic characteristics of two different reactions using given values for enthalpy

Entropy Change Analysis

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

Equilibrium Constant and Gibbs Free Energy

A reaction at equilibrium is characterized by an equilibrium constant (K). The relationship between

Exploring the Nernst Equation in Dynamic Systems

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

FRQ 3: Galvanic Cell Voltage and Reaction Quotient

A galvanic cell operating under non‐standard conditions is described by the Nernst equation: $$E =

FRQ 14: Determining Reaction Spontaneity from Reduction Potentials

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

Gibbs Free Energy Calculation and Reaction Analysis

A media headline claims that a certain reaction is thermodynamically favored at room temperature bec

Gibbs Free Energy under Non-Standard Conditions

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

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

Redox Reaction Mechanisms and Energy Changes

In an organic synthesis experiment, a redox reaction proceeds through multiple steps involving elect

Relating Equilibrium Constant and Free Energy

For a particular reaction at 298 K, the equilibrium constant (K) is measured to be 55. Use the relat

Relating Gibbs Free Energy and Electric Current in Electrochemical Cells

A researcher investigates the relationship between the Gibbs free energy change (∆G°) of a cell reac

Temperature Effects on Electroplating

An experimental study examines how temperature affects the rate of electroplating. The following dat

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

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

Voltage and Redox Reaction Spontaneity

Using the relation $$\Delta G^\circ = -nF E^\circ$$, analyze the spontaneity of a redox reaction.