Skip to main content
Ch.14 - Chemical Kinetics
Brown - Chemistry: The Central Science 15th Edition
Brown15th EditionChemistry: The Central ScienceISBN: 9780137542970Non è quello che usi tu?Cambia libro di testo
Capitolo 14, Problema 43a

As described in Exercise 14.41, the decomposition of sulfuryl chloride (SO2Cl2) is a first-order process. The rate constant for the decomposition at 660 K is 4.5 × 10-2 s-1. (a) If we begin with an initial SO2Cl2 pressure of 450 torr, what is the partial pressure of this substance after 60 s?

Guida verificata passo dopo passo
1
Identify the type of reaction: The decomposition of sulfuryl chloride (SO2Cl2) is a first-order reaction. This means the rate of reaction is directly proportional to the concentration of SO2Cl2.
Use the first-order rate equation: The formula for a first-order reaction is \( P_t = P_0 e^{-kt} \), where \( P_t \) is the partial pressure at time \( t \), \( P_0 \) is the initial pressure, \( k \) is the rate constant, and \( t \) is the time.
Substitute the known values into the equation: You have \( P_0 = 450 \) torr, \( k = 4.5 \times 10^{-2} \) s\(^{-1}\), and \( t = 60 \) s. Plug these values into the equation to find \( P_t \).
Calculate the exponent: Compute \( -kt \) which is \( -4.5 \times 10^{-2} \times 60 \). This will give you the exponent for the exponential function.
Evaluate the expression: Calculate \( e^{-kt} \) using the exponent from the previous step, then multiply by the initial pressure \( P_0 \) to find the partial pressure \( P_t \) after 60 seconds.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
11m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

First-Order Reactions

First-order reactions are chemical processes where the rate of reaction is directly proportional to the concentration of one reactant. This means that as the concentration decreases, the rate of reaction also decreases. The mathematical representation involves a natural logarithm, allowing for the calculation of concentration or pressure over time using the equation: ln([A]₀/[A]) = kt, where [A]₀ is the initial concentration, [A] is the concentration at time t, k is the rate constant, and t is time.
Video consigliato:
Percorso guidato
02:29
First-Order Reactions

Rate Constant (k)

The rate constant (k) is a proportionality factor in the rate law of a chemical reaction, reflecting the speed of the reaction at a given temperature. For first-order reactions, k has units of s⁻¹, indicating how quickly the reactant is consumed. The value of k can vary with temperature, and it is crucial for calculating the concentration or pressure of reactants over time in kinetic studies.
Video consigliato:
Percorso guidato
01:14
Equilibrium Constant K

Partial Pressure

Partial pressure is the pressure exerted by a single component of a gas mixture. In the context of a reaction, it helps in understanding how the concentration of a reactant changes over time. For gases, the partial pressure can be related to the number of moles of the gas and the volume of the container, following Dalton's Law of Partial Pressures, which states that the total pressure is the sum of the partial pressures of each gas in the mixture.
Video consigliato:
Percorso guidato
00:48
Partial Pressure Calculation