2019 AP Chemistry Exam Flashcards

Questions and Answers

In which of the following processes will ΔS° be negative?

Ge(g) + 2Cl2(g) ⇄ GeCl4(g)

H2(g) + I2(g) ⇄ 2HI(g)

0.1M KI(aq)

Cl2(g) → Cl2(l) (correct)

Which of the three solutions has the greatest electrical conductivity?

0.1M KI(aq)

What happens to the reaction after additional iodine gas is added?

The rate of the forward reaction becomes greater than the rate of the reverse reaction.

What element has large differences in the first five ionization energies?

Al Signup and view all the answers

What can be concluded about the particle in aqueous solution?

The particle must be an anion because the positive end of each water molecule is pointed toward it. Signup and view all the answers

What is the best technique to separate hexane and octane?

Distillation Signup and view all the answers

What is the value of the equilibrium constant for the reaction 2GeCl4(g) ⇄ 2Ge(g) + 4Cl2(g)?

1×10^−20 Signup and view all the answers

What does an enzyme do to catalyze a biochemical reaction?

Binds temporarily to reactant molecules to lower the activation energy of the reaction. Signup and view all the answers

Which of the following diagrams best represents the structure of solid KF?

+-+-+-+ Signup and view all the answers

What is the net ionic equation for the reaction in the electrochemical cell?

2Ag(aq) + Zn(s) → 2Ag(s) + Zn2+(aq) Signup and view all the answers

What is the value of E° for the electrochemical cell?

1.56V Signup and view all the answers

What mass of LiOH(s) is needed to react with all of the CO2(g) produced by an astronaut in one day?

960g Signup and view all the answers

What rate law is consistent with the decomposition of NO2(g)?

Rate = k[NO2]^2 Signup and view all the answers

Why is the peak on the He spectrum farther to the left and higher than on the H spectrum?

He has a greater nuclear charge than H and an additional electron in the same energy level. Signup and view all the answers

What is the molecular formula of the unknown compound?

C4H8O2 Signup and view all the answers

Why are the combustion reactions represented exothermic?

The energy required to break the bonds in the reactants is less than the energy released in forming the bonds in the products. Signup and view all the answers

Which compound is more soluble in water?

Propanol Signup and view all the answers

Study Notes

Thermodynamics and Kinetics

A process with a negative ΔS° signifies a decrease in disorder, exemplified by the transition from gaseous Cl2 to liquid Cl2.
Electrical conductivity in solutions is highest for 0.1M KI due to complete dissociation into ions in water.

Chemical Equilibrium

In the equilibrium reaction of H2 and I2 to form HI, adding more iodine gas increases the forward reaction rate, leading to a shift in equilibrium.
The equilibrium constant (K) for the reaction 2GeCl4 ⇄ 2Ge + 4Cl2 is the inverse of the K for Ge + 2Cl2 ⇄ GeCl4, calculated as 1 x 10^-20.

Element and Ion Properties

The significant difference between the third and fourth ionization energies indicates the element is Aluminum (Al), suggesting a filled outer shell.
A particle in aqueous solution exhibiting interaction with water's positive ends is identified as an anion.

Laboratory Techniques

Distillation is the most effective method for separating hexane and octane, capitalizing on different boiling temperatures due to varied intermolecular forces.

Biochemical Reactions

Enzymes catalyze reactions by temporarily binding to substrates, which lowers the activation energy required for the reaction to proceed.

Solid Structures

Solid KF exhibits a structure of alternating charged particles with equal size, demonstrating ionic lattice properties.

Electrochemistry

The net ionic reaction for the electrochemical cell involving silver and zinc is represented as 2Ag + Zn → 2Ag(s) + Zn^2+(aq).
The standard cell potential (E°) for the electrochemical reaction is calculated to be 1.56 V.

Stoichiometry and Mass Calculations

To remove 880 g of CO2 produced daily by an astronaut, 960 g of LiOH is required for the reaction to occur completely.

Reaction Kinetics

The observed data from NO2 decomposition support a second-order rate law represented by Rate = k[NO2]^2.

Atomic Structure and Electron Configuration

The peak in the photoelectron spectra for Helium (He) is shifted compared to Hydrogen (H) due to He's greater nuclear charge and an extra electron, affecting binding energies.

Molecular Formulas

The molecular formula for the unknown compound is determined to be C4H8O2.

Energy Changes in Reactions

Combustion reactions are exothermic because they release more energy in forming products than the energy required to break bonds in reactants.

Solubility and Intermolecular Forces

Propanol exhibits greater solubility in water than ethane due to its ability to form hydrogen bonds with water molecules, unlike ethane.

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Description

Test your knowledge with these flashcards designed for the 2019 AP Chemistry exam. Each card covers key concepts and reactions, providing a quick review of essential topics. Perfect for students preparing for the exam to enhance their understanding of chemical processes and principles.