/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 17 (a) What is meant by the term re... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 14: Problem 17

(a) What is meant by the term reaction rate? (b) Name three factors that can affect the rate of a chemical reaction. \((\mathbf{c})\) Is the rate of disappearance of reactants always the same as the rate of appearance of products?

Short Answer

Expert verified
(a) Reaction rate is the speed of a chemical reaction. (b) Temperature, concentration, and catalysts affect it. (c) No, their rates are related by stoichiometry.

Step by step solution

01

Understanding Reaction Rate

The reaction rate refers to the speed at which a chemical reaction occurs. It is defined as the change in concentration of reactants or products per unit time. Reaction rates can be measured in moles per liter per second (mol/L/s), where we either track how quickly reactants are consumed or how quickly products are formed.
02

Identifying Factors Affecting Reaction Rate

Several factors can influence the rate of a chemical reaction. Three important factors include: (1) Temperature: Increasing temperature generally increases reaction rates due to higher kinetic energy, leading to more collisions between molecules. (2) Concentration: Higher concentration of reactants usually leads to a faster reaction rate since there are more molecules available to collide. (3) Catalysts: Catalysts increase the rate of a reaction by lowering the activation energy needed, without being consumed in the process.
03

Comparing Rates of Disappearance and Appearance

The rate of disappearance of reactants and the rate of appearance of products are related but are not always numerically the same. In a balanced chemical equation, the stoichiometric coefficients determine this relationship. For example, if reaction \[ aA \longrightarrow bB \]is considered, then the rate of appearance of products is scaled by the ratio of their stoichiometric coefficients to the rate of disappearance of reactants.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Factors Affecting Reaction Rate
Understanding the factors that affect reaction rates is essential to controlling chemical reactions. Here's a quick dive into the three main factors:
  • Temperature: As temperature increases, molecules move faster. This increased speed means more frequent and energetic collisions between reactant molecules, often resulting in a faster reaction rate.
  • Concentration: With more reactant particles in a given volume, there are more opportunities for particles to collide and react. Thus, higher concentrations generally lead to higher reaction rates.
  • Catalysts: Catalysts are fascinating because they speed up reactions without being consumed. They work by lowering the activation energy, making it easier for reactions to proceed.
Examining these factors gives us tools to manipulate the speed of reactions in various applications.
Temperature and Reaction Rate
The role of temperature is profound when it comes to influencing reaction rates. When we increase the temperature, the kinetic energy of the molecules also increases. This heightened energy results in more frequent and forceful collisions among molecules.
The beautiful underlying principle is the Arrhenius Equation, which quantitatively shows how reaction rates increase with temperature. In essence, even a small change in temperature can lead to a significant change in rate, as more molecules have the necessary energy to overcome activation energy barriers.
This principle is used in many practical settings, such as in cooking to speed up food preparation and in industrial processes to achieve more efficient chemical production. It highlights the vital relationship between kinetic energy and reaction speed.
Catalysts in Chemical Reactions
Catalysts are game-changers in the world of chemistry. They provide an alternate pathway for a reaction with a lower activation energy. This principle is key to understanding their incredible effect on reaction rates.
In practical terms, catalysts allow reactions to proceed faster at lower temperatures than would be otherwise required. This can save both energy and time, which is why catalysts are so widely used in industry.
Importantly, catalysts are not consumed in the reaction, meaning they can continue to facilitate multiple rounds of reactions. Take enzymes, for example, which are biological catalysts. They enable biochemical reactions within living organisms to proceed at rates necessary for life. Understanding catalysts highlights the elegance of chemistry in enhancing process efficiency.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

The first-order rate constant for reaction of a particular organic compound with water varies with temperature as follows: \begin{tabular}{ll} \hline Temperature \((\mathrm{K})\) & Rate Constant \(\left(\mathrm{s}^{-1}\right)\) \\ \hline 300 & \(3.2 \times 10^{-11}\) \\ 320 & \(1.0 \times 10^{-9}\) \\ 340 & \(3.0 \times 10^{-8}\) \\ 355 & \(2.4 \times 10^{-7}\) \\ \hline \end{tabular} From these data, calculate the activation energy in units of \(\mathrm{kJ} / \mathrm{mol}\).

Based on their activation energies and energy changes and assuming that all collision factors are the same, rank the following reactions from slowest to fastest. (a) \(E_{a}=75 \mathrm{~kJ} / \mathrm{mol} ; \Delta E=-20 \mathrm{~kJ} / \mathrm{mol}\) (b) \(E_{a}=100 \mathrm{~kJ} / \mathrm{mol} ; \Delta E=+30 \mathrm{~kJ} / \mathrm{mol}\) (c) \(E_{a}=85 \mathrm{~kJ} / \mathrm{mol} ; \Delta E=-50 \mathrm{~kJ} / \mathrm{mol}\)

What is the molecularity of each of the following elementary reactions? Write the rate law for each. (a) \(\mathrm{H}_{2} \mathrm{O}(l)+\mathrm{CN}^{-}(a q) \longrightarrow \mathrm{HCN}(a q)\) (b) \(\mathrm{CH}_{3} \mathrm{Cl}(\mathrm{solv})+\mathrm{OH}^{-}(\mathrm{solv}) \longrightarrow \mathrm{CH}_{3} \mathrm{OH}(\mathrm{solv})+\mathrm{Cl}^{-}(\mathrm{solv})\) (c) \(\mathrm{N}_{2} \mathrm{O}_{4}(g) \rightarrow 2 \mathrm{NO}_{2}\)

From the following data for the second-order gas-phase decomposition of HI at \(430^{\circ} \mathrm{C},\) calculate the second-order rate constant and half- life for the reaction: \begin{tabular}{rl} \hline Time (s) & [HIYmol dm \(^{-3}\) \\ \hline 0 & 1 \\ 100 & 0.89 \\ 200 & 0.8 \\ 300 & 0.72 \\ 400 & 0.66 \end{tabular}

The activation energy of an uncatalyzed reaction is \(95 \mathrm{~kJ} / \mathrm{mol}\). The addition of a catalyst lowers the activation energy to \(55 \mathrm{~kJ} / \mathrm{mol}\). Assuming that the collision factor remains the same, by what factor will the catalyst increase the rate of the reaction at (a) \(25^{\circ} \mathrm{C},(\mathbf{b}) 125^{\circ} \mathrm{C} ?\)
See all solutions

Recommended explanations on Chemistry Textbooks

Chemistry Branches

Read Explanation

The Earths Atmosphere

Read Explanation

Inorganic Chemistry

Read Explanation

Physical Chemistry

Read Explanation

Ionic and Molecular Compounds

Read Explanation

Chemical Analysis

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.