Question 1

Sucrose, C₁₂H₂₂O₁₁, reacts slowly with water in the presence of an acid to form two other sugars, glucose and fructose, both of which have the same molecular formulas, but different structures. C₁₂H₂₂O₁₁ + H₂O $\rarr$ C₆H₁₂O₆ (glucose)+ C₆H₁₂O₆ (fructose) The reaction is first order and has a rate constant of 6.2 * 10^-5 /s at 35°C when the H⁺ concentration is 0.10 M. Suppose that the initial concentration of sucrose in the solution is 0.40 M. How many minutes will it take for the sucrose concentration to drop to 0.30 M?

Accepted Answer

The answer of Sucrose, C₁₂H₂₂O₁₁, reacts slowly with water in...

Question 2

The first-order decomposition of SO₂Cl₂ to sulfur dioxide gas and chlorine gas at 320°C has a half-life of 8.75 hr. If one begins with 600. mmHg of pure SO₂Cl₂ in a 5.00-L flask at 320°C, how long does it take for the total pressure in the flask to rise to 1.000 atm?

Accepted Answer

The answer of The first-order decomposition of SO₂Cl₂ to sulfur...

Question 3

Sucrose, C₁₂H₂₂O₁₁, reacts slowly with water in the presence of an acid to form two other sugars, glucose and fructose, both of which have the same molecular formulas, but different structures. C₁₂H₂₂O₁₁ + H₂O $\rarr$C₆H₁₂O₆ (glucose)+ C₆H₁₂O₆ (fructose) The reaction is first order and has a rate constant of 6.2 * 10^-5/s at 35°C when the H⁺ concentration is 0.10 M. Suppose that the initial concentration of sucrose in the solution is 0.40 M. What will the sucrose concentration be after 2.0 hours?

Accepted Answer

The answer of Sucrose, C₁₂H₂₂O₁₁, reacts slowly with water in...

Question 4

Aspirin, C₉H₈O₄, slowly decomposes at room temperature by reacting with water in the atmosphere to produce acetic acid, HC₂H₃O₂, and 2-hydroxybenzoic acid, C₇H₆O₃ (this is why old bottles of aspirin often smell like vinegar): C₉H₈O₄ + H₂O $\rarr$HC₂H₃O₂ + C₇H₆O₃ Concentration and rate data for this reaction are given below. Write the rate law for this reaction and calculate k (be sure to include the correct units).

Accepted Answer

The answer of Aspirin, C₉H₈O₄, slowly decomposes at room temperature...

Question 5

In which of the forms listed below would 0.5 g aluminum react the fastest with gaseous chlorine at 25°C?

Accepted Answer

When a solid is divided into smaller pieces, its surface area increases, which provides more opportunities for the reactant particles to collide and react. Therefore, the aluminum divided into 1,000 pieces will have the largest surface area and react the fastest with gaseous chlorine.

Question 6

At a particular temperature the first-order gas-phase reaction N₂O₅ $\rarr$ 2NO₂ + ¹/₂O₂ has a half-life for the disappearance of dinitrogen pentoxide of 5130 s. Suppose 0.450 atm of N₂O₅ is introduced into an evacuated 2.00 L flask. What will be the total gas pressure inside the flask after 3.00 hours?

Accepted Answer

For a first-order reaction, the half-life ($t_{1/2}$) is given by $t_{1/2} = \frac{0.693}{k}$, where $k$ is the rate constant. Given the half-life is 5130 s, we can find $k$, but it's not directly needed for this calculation. The key is understanding that the pressure of a gas in a closed container is directly proportional to the number of moles of gas (assuming ideal gas behavior and constant temperature and volume).The reaction is: $$2N_2O_5 \rightarrow 4NO_2 + O_2$$Initially, there are 0.450 atm of $N_2O_5$. After 3 hours (10800 s), we can calculate the fraction of $N_2O_5$ that has reacted using the first-order kinetics formula: $$N_t = N_0 \cdot e^{-kt}$$However, to simplify, we can use the concept of half-lives. In 3 hours (10800 s), there are $10800 s / 5130 s = 2.1$ half-lives. After each half-life, the amount of reactant decreases by half. So, after 2.1 half-lives, a fraction of the original $N_2O_5$ remains, but we're more interested in the total pressure, which comes from the total moles of gas.For every 2 moles of $N_2O_5$ reacted, 5 moles of product gases are produced (4 moles of $NO_2$ and 1 mole of $O_2$). This means the total moles of gas increase, and thus the pressure increases, as the reaction proceeds.Without calculating the exact fraction of $N_2O_5$ that remains (which requires the rate constant $k$), we know the pressure will increase due to the stoichiometry of the reaction. The correct answer must account for an increase in total pressure due to the production of more moles of gas than were consumed. Among the options, only choice A) 0.969 atm makes sense as it represents an increase in pressure from the original 0.450 atm, consistent with the expected outcome of the reaction proceeding and producing more moles of gas. The detailed calculation would involve determining the exact fraction of $N_2O_5$ that remains unreacted and the corresponding increase in moles of gas due to the reaction, then applying the ideal gas law to find the total pressure. However, without the exact calculations, understanding the reaction stoichiometry and the effect on total gas moles and pressure leads to the conclusion that A) is the correct choice.

Question 7

The first-order decomposition of phosphene to phosphorus and hydrogen 4PH₃(g)$\rarr$P₄(g)+ 6H₂(g)has a half-life of 35.0 s at 680°C. Starting with 520 mmHg of pure phosphene in an 8.00-L flask at 680°C, how long will it take for the total pressure in the flask to rise to 1.000 atm?

Accepted Answer

The answer of The first-order decomposition of phosphene to phosphorus...

Question 8

Nitrogen pentoxide decomposes by a first-order process yielding N₂O₄ and oxygen. 2N₂O₅ $\rarr$ 2N₂O₄ + O₂ At a given temperature, the half-life of N₂O₅ is 0.90 hr. What is the first-order rate constant for N₂O₅ decomposition?

Accepted Answer

The answer of Nitrogen pentoxide decomposes by a first-order process...

Question 9

The rate constant for a certain first-order reaction is 0.40/min. What is the initial rate in mole/L·min, if the initial concentration of the compound involved is 0.50 mol/L?

Accepted Answer

The answer of The rate constant for a certain first-order...

Question 10

For the reaction whose rate law is rate = k[X], a plot of which of the following is a straight line?

Accepted Answer

The given rate law, rate = k[X], indicates a first-order reaction with respect to [X]. For first-order reactions, plotting the natural logarithm of the concentration of the reactant ([X]) versus time yields a straight line, according to the first-order kinetics equation ln[X] = -kt + ln[X0], where [X0] is the initial concentration of the reactant.

Question 11

What is the rate law that corresponds to the data shown for the reaction 2A + B $\rarr$ C?

Accepted Answer

The answer of What is the rate law that corresponds...

Question 12

At a particular temperature the first-order gas-phase reaction 2N₂O₅ $\rarr$2N₂O₄ + O₂ has a half-life for the disappearance of dinitrogen pentoxide of 3240 s. If 1.00 atm of N₂O₅ is introduced into an evacuated 5.00 L flask, what will be the total pressure of the gases in the flask after 1.50 hours?

Accepted Answer

The rate constant for a first-order reaction can be determined using the half-life equation: t1/2 = ln 2 / k where t1/2 is the half-life and k is the rate constant. Rearranging this equation gives: k = ln 2 / t1/2 Substituting the given half-life of 3240 s: k = ln 2 / 3240 s = 2.14 x 10^-4 s^-1 The rate law for a first-order reaction can be written as: rate = k [N₂O₅] Using the ideal gas law, we can determine the initial number of moles of N₂O₅: n = PV / RT = (1.00 atm)(5.00 L) / (0.0821 L·atm/mol·K)(298 K) = 0.203 mol Since two moles of N₂O₅ react to produce two moles of N₂O₄ and one mole of O₂, the number of moles of N₂O₅ remaining after time t can be expressed as: [N₂O₅]t = [N₂O₅]0 e^-kt where [N₂O₅]0 is the initial concentration of N₂O₅. Substituting the given time of 1.50 hours (5400 s) and the calculated rate constant: [N₂O₅]t = (0.203 mol / 5.00 L) e^-(2.14 × 10^-4 s^-1 × 5400 s) = 0.038 mol / L The total number of moles of gas in the flask at time t is: ntotal = nN₂O₅ + nN₂O₄ + nO₂ The number of moles of N₂O₄ can be calculated from the balanced equation: nN₂O₄ = 0.203 mol - [N₂O₅]t = 0.203 mol - 0.038 mol = 0.165 mol The number of moles of O₂ can also be calculated from the balanced equation: nO₂ = nN₂O₅ = 0.038 mol Therefore, the total number of moles of gas in the flask at time t is: ntotal = 0.203 mol + 0.165 mol + 0.038 mol = 0.406 mol Finally, the total pressure of the gases in the flask can be calculated using the ideal gas law: Ptotal = ntotal RT / V = (0.406 mol)(0.0821 L·atm/mol·K)(298 K) / 5.00 L = 1.34 atm Therefore, the answer is (E) 1.34 atm.

Question 13

When acetaldehyde at a pressure of 364 mmHg is introduced into an evacuated 500. mL flask at 518°C, the half-life for the second-order decomposition process, CH₃CHO $\rarr$ CH₄ + CO, is 410. s. What will the total pressure in the flask be after 1.00 hour?

Accepted Answer

The answer of When acetaldehyde at a pressure of 364...

Question 14

A nuclear stress test utilizes a gamma-emitting radioisotope such as thallium-201 to follow the flow of blood through the heart - first at rest, and then under stress. The first-order rate constant for the decay of thallium-201 is 9.5 x 10^-3 hr^-1. Calculate how long it takes for the amount of thallium-201 to fall to 5.0% of its original value.

Accepted Answer

The answer of A nuclear stress test utilizes a gamma-emitting...

Question 15

For the reaction represented below, the experimental rate law is given by rate = k [(CH₃)₃CCl]. (CH₃)₃CCl(aq)+ OH^-$\rarr$(CH₃)₃COH(aq)+ Cl^- If some solid sodium hydroxide were added to a solution in which [(CH₃)₃CCl] = 0.01 M and [NaOH] = 0.10 M, which of the following would be true? (Assume the temperature and volume remain constant.)

Accepted Answer

The answer of For the reaction represented below, the experimental...

Question 16

Use the table of data shown below to calculate the average rate of the reaction A$\rarr$B between 10 s and 20 s.

Accepted Answer

The answer of Use the table of data shown below...

Question 17

Peroxodisulfate ion can oxidize iodide ions to iodine according to the balanced equation S₂O₈^2-+ 2I^- $\rarr$2SO₄^2- + I₂. The reaction is catalyzed by certain chemical species. Identify the catalyst in the following mechanism: Step 1: Fe³⁺ + 2I^- $\rarr$ Fe²⁺ + I₂ Step 2: S₂O₈^2- + Fe²⁺ $\rarr$ 2SO₄^2- + Fe³⁺

Accepted Answer

Fe³⁺ is the catalyst as it is regenerated at the end of the reaction mechanism.

Question 18

An experimental drug, D, is known to decompose in the blood stream. Tripling the concentration of the drug increases the decomposition rate by a factor of nine. Write the rate law for decomposition of D and give the units of the rate constant.

Accepted Answer

The answer of An experimental drug, D, is known to...

Question 19

At a certain temperature, the data below were collected for the reaction below. 2ICl + H₂ $\rarr$I₂ + 2HCl. Determine the rate law for the reaction.

Accepted Answer

The answer of At a certain temperature, the data below...

Question 20

At a certain temperature, the data below were collected for the reaction below. 2ICl + H₂ $\rarr$I₂ + 2HCl. Determine the rate constant for the reaction.

Accepted Answer

The answer of At a certain temperature, the data below...

Quiz 14: Chemical Kinetics

The first-order decomposition of SO₂Cl₂ to sulfur dioxide gas and chlorine gas at 320°C has a half-life of 8.75 hr. If one begins with 600. mmHg of pure SO₂Cl₂ in a 5.00-L flask at 320°C, how long does it take for the total pressure in the flask to rise to 1.000 atm?

In which of the forms listed below would 0.5 g aluminum react the fastest with gaseous chlorine at 25°C?

The first-order decomposition of phosphene to phosphorus and hydrogen 4PH₃(g) $\rarr$ P₄(g) + 6H₂(g) has a half-life of 35.0 s at 680°C. Starting with 520 mmHg of pure phosphene in an 8.00-L flask at 680°C, how long will it take for the total pressure in the flask to rise to 1.000 atm?

Nitrogen pentoxide decomposes by a first-order process yielding N₂O₄ and oxygen. 2N₂O₅ $\rarr$ 2N₂O₄ + O₂ At a given temperature, the half-life of N₂O₅ is 0.90 hr. What is the first-order rate constant for N₂O₅ decomposition?

The rate constant for a certain first-order reaction is 0.40/min. What is the initial rate in mole/L·min, if the initial concentration of the compound involved is 0.50 mol/L?

For the reaction whose rate law is rate = k[X], a plot of which of the following is a straight line?

What is the rate law that corresponds to the data shown for the reaction 2A + B $\rarr$ C? $What is the rate law that corresponds to the data shown for the reaction 2A + B \rarr C?$

When acetaldehyde at a pressure of 364 mmHg is introduced into an evacuated 500. mL flask at 518°C, the half-life for the second-order decomposition process, CH₃CHO $\rarr$ CH₄ + CO, is 410. s. What will the total pressure in the flask be after 1.00 hour?

Use the table of data shown below to calculate the average rate of the reaction A $\rarr$ B between 10 s and 20 s. $Use the table of data shown below to calculate the average rate of the reaction A \rarr B between 10 s and 20 s.$

An experimental drug, D, is known to decompose in the blood stream. Tripling the concentration of the drug increases the decomposition rate by a factor of nine. Write the rate law for decomposition of D and give the units of the rate constant.

Quiz 14: Chemical Kinetics

The first-order decomposition of SO2Cl2 to sulfur dioxide gas and chlorine gas at 320°C has a half-life of 8.75 hr. If one begins with 600. mmHg of pure SO2Cl2 in a 5.00-L flask at 320°C, how long does it take for the total pressure in the flask to rise to 1.000 atm?

In which of the forms listed below would 0.5 g aluminum react the fastest with gaseous chlorine at 25°C?

The first-order decomposition of phosphene to phosphorus and hydrogen 4PH3(g) →\rarr→ P4(g) + 6H2(g) has a half-life of 35.0 s at 680°C. Starting with 520 mmHg of pure phosphene in an 8.00-L flask at 680°C, how long will it take for the total pressure in the flask to rise to 1.000 atm?

Nitrogen pentoxide decomposes by a first-order process yielding N2O4 and oxygen. 2N2O5 →\rarr→ 2N2O4 + O2 At a given temperature, the half-life of N2O5 is 0.90 hr. What is the first-order rate constant for N2O5 decomposition?

The rate constant for a certain first-order reaction is 0.40/min. What is the initial rate in mole/L·min, if the initial concentration of the compound involved is 0.50 mol/L?

For the reaction whose rate law is rate = k[X], a plot of which of the following is a straight line?

What is the rate law that corresponds to the data shown for the reaction 2A + B →\rarr→ C?

When acetaldehyde at a pressure of 364 mmHg is introduced into an evacuated 500. mL flask at 518°C, the half-life for the second-order decomposition process, CH3CHO →\rarr→ CH4 + CO, is 410. s. What will the total pressure in the flask be after 1.00 hour?

Use the table of data shown below to calculate the average rate of the reaction A →\rarr→ B between 10 s and 20 s.

An experimental drug, D, is known to decompose in the blood stream. Tripling the concentration of the drug increases the decomposition rate by a factor of nine. Write the rate law for decomposition of D and give the units of the rate constant.

At a certain temperature, the data below were collected for the reaction below. 2ICl + H2 →\rarr→ I2 + 2HCl. Determine the rate law for the reaction.

At a certain temperature, the data below were collected for the reaction below. 2ICl + H2 →\rarr→ I2 + 2HCl. Determine the rate constant for the reaction.

The first-order decomposition of SO₂Cl₂ to sulfur dioxide gas and chlorine gas at 320°C has a half-life of 8.75 hr. If one begins with 600. mmHg of pure SO₂Cl₂ in a 5.00-L flask at 320°C, how long does it take for the total pressure in the flask to rise to 1.000 atm?

The first-order decomposition of phosphene to phosphorus and hydrogen 4PH₃(g) $\rarr$ P₄(g) + 6H₂(g) has a half-life of 35.0 s at 680°C. Starting with 520 mmHg of pure phosphene in an 8.00-L flask at 680°C, how long will it take for the total pressure in the flask to rise to 1.000 atm?

Nitrogen pentoxide decomposes by a first-order process yielding N₂O₄ and oxygen. 2N₂O₅ $\rarr$ 2N₂O₄ + O₂ At a given temperature, the half-life of N₂O₅ is 0.90 hr. What is the first-order rate constant for N₂O₅ decomposition?

What is the rate law that corresponds to the data shown for the reaction 2A + B $\rarr$ C? $What is the rate law that corresponds to the data shown for the reaction 2A + B \rarr C?$

When acetaldehyde at a pressure of 364 mmHg is introduced into an evacuated 500. mL flask at 518°C, the half-life for the second-order decomposition process, CH₃CHO $\rarr$ CH₄ + CO, is 410. s. What will the total pressure in the flask be after 1.00 hour?

Use the table of data shown below to calculate the average rate of the reaction A $\rarr$ B between 10 s and 20 s. $Use the table of data shown below to calculate the average rate of the reaction A \rarr B between 10 s and 20 s.$