Question

For the reaction \(\mathrm{A}(\mathrm{g}) \longrightarrow \mathrm{B}(\mathrm{g})\), sketch two curves on the same set of axes that show (a) The formation of product as a function of time (b) The consumption of reactant as a function of time

Short answer

Draw two curves: one starts at zero and increases (formation of B), the other starts high and decreases (consumption of A).

Step-by-step solution

- Understanding the Reaction

Consider the given reaction \(\text{A}(g) \rightarrow \text{B}(g)\). This means that reactant A is consumed over time to form product B.

- Define Axes

On the graph, define the x-axis as time (t) and the y-axis as the concentration of species (either \[\text{A}(g)\] or \[\text{B}(g)\]).

- Sketching the Formation of Product B

Since product B is formed from reactant A, start the curve for \[\text{B}(g)\] at zero on the y-axis. As time progresses, the concentration of \[\text{B}(g)\] increases. Draw a curve that starts at the origin (0,0) and increases to a maximum value.

- Sketching the Consumption of Reactant A

Reactant A is consumed over time, so start the curve for \[\text{A}(g)\] at a maximum value on the y-axis. As time progresses, the concentration of \[\text{A}(g)\] decreases. Draw a curve that starts from the maximum value and decreases towards zero.

- Labeling Curves

Label the increasing curve as \[\text{B}(g)\] to indicate the formation of product and the decreasing curve as \[\text{A}(g)\] to indicate the consumption of reactant.

Key concepts

reaction rates

Reaction rates tell us how fast a reaction happens. Imagine you're watching a race and you want to know the speed of each runner. In chemistry, we'd like to know the speed at which reactants turn into products. This is what reaction rates measure. The reaction rate can be affected by several factors:

• Concentration of reactants: Higher concentration means more particles are colliding, so the reaction is faster.
• Temperature: Higher temperatures give particles more energy, leading to more collisions.
• Surface area: More surface area means more opportunity for collisions.
• Catalysts: They speed up reactions without being consumed.

It's essential to understand that reaction rates aren't always constant. They can change as the reactants are used up. Initially, the rate might be higher, but it slows down as the concentration of reactants decreases.

concentration vs. time

To understand how a reaction progresses, it’s useful to plot concentration versus time. This shows us how the amounts of reactants and products change over time.
Let’s break this down further:

• For reactants: If you start with a certain concentration of a reactant, you’ll see this concentration decrease as the reaction proceeds. This would look like a downward-sloping curve.
• For products: Starting with zero or very little product at the beginning, you'll watch its concentration increase over time, creating an upward-sloping curve.

Using these graphs, you can determine the speed of the reaction and when the reaction might stop (when the reactants are used up). These visual aids are powerful tools in understanding the dynamics of chemical reactions.
Consider the axes: Time always goes on the x-axis, and concentration on the y-axis. The particular shape of your curves will depend on the reaction specifics, but understanding these basics is crucial.

chemical reactions

Chemical reactions involve the transformation of reactants into products. Think of it as baking a cake: the ingredients (reactants) mix and cook to form the finished cake (products). Here’s what to remember:

• Reactants are substances you start with before the reaction occurs.
• Products are substances formed as a result of the reaction.

In the reaction \(\text{A}(g) \rightarrow \text{B}(g)\), A is the reactant and B is the product. Over time, A is consumed to form more and more of B. This is the basis of many reactions we observe daily.
When plotting these on a graph:

• The curve for A, the reactant, will start high and drop as time progresses. This shows A being used up.
• The curve for B, the product, will start low and rise as A is converted to B.

By practicing and observing these graphs, you can get a deeper understanding of how chemical reactions progress and what factors might influence them.