For each of the questions, four choices have been provided. Select the correct alternative. Identify the correct sequence of steps in an experiment to show the effect of temperature on the rate of the reaction. (1) Measuring the volumes of \(\mathrm{H}_{2}\) gas liberated in the two test tubes. (2) Heating the test tube \(\mathrm{B}\) by \(10^{\circ} \mathrm{C}\). (3) Comparison of relative volumes of \(\mathrm{H}_{2}\) liberated in test tubes \(\mathrm{B}\) and \(\mathrm{A}\). (4) Addition of same concentration of \(\mathrm{HCl}\) to the two test tubes. (5) Taking equal masses of fine granules of zinc in two test tubes \(A\) and \(B\). (a) \(3,4,5,1,2\) (b) \(5,4,2,1,3\) (c) \(2,1,3,5,4\) (d) \(5,4,2,3,1\)

Chemical kinetics is the branch of chemistry that studies the rates of chemical reactions, the factors that affect these rates, and the mechanisms by which reactions proceed. Understanding kinetics allows chemists to control and optimize reactions, whether they are seeking to accelerate a desired process or slow down a degradation reaction.

The rate of a chemical reaction is usually expressed as the change in concentration of a reactant or product per unit time. In an educational setting, students often visualize and measure these rates through experiments that yield tangible, observable results such as the production of gas, color change, or temperature change in a reaction mixture.

For instance, in the textbook experiment involving zinc and hydrochloric acid, measuring the hydrogen gas evolved allows students to concretely see the reaction's progression. The amount of gas produced is directly related to the speed of the reaction, making it a simple yet illustrative example of chemical kinetics at work.

The temperature effect on reaction rate is a fundamental concept in chemical kinetics. Generally, as the temperature increases, reaction rates accelerate. This is because higher temperatures provide reactant molecules with more kinetic energy, which increases the frequency and energy of collisions between molecules.

Understanding this relationship is crucial for controlling chemical reactions in various industrial and laboratory settings. For example, increasing the temperature can be used to speed up sluggish reactions, while cooling might be required to stabilize reactive or volatile substances.

In the textbook experiment, the comparison between the test tubes at different temperatures demonstrates this principle. By heating only one of the test tubes, students can observe a higher rate of hydrogen gas production, thus confirming that temperature is a key factor that directly impacts the rate of a chemical reaction.

Measuring the volume of gas produced during a chemical reaction is a common method for analyzing reaction rates. The technique is especially useful for reactions that liberate a gas as one of the products, such as when a metal reacts with an acid to produce hydrogen.

To accurately measure the gas volume, students often use apparatus like a graduated cylinder or a gas syringe. This process provides a visual and quantifiable aspect to the reaction, allowing for comparative and time-dependent studies of reaction rates. For instance, in the experiment involving the reaction between zinc and hydrochloric acid, the collection and measurement of hydrogen gas released are pivotal to understanding how the rate of reaction is influenced by the temperature.

By incorporating step-by-step instructions and presenting the methods clearly and concisely, such experiments greatly enhance the student's ability to grasp the relationship between reaction conditions and the kinetics involved. They learn how to perform controlled experiments, measure outcomes precisely, and deduce the effects of different variables on the rate of a reaction.