Rates of Reaction and Reversible Reactions Flashcards
(16 cards)
What are the main factors that affect the rate of a reaction?
Surface area of solids, concentration of solutions, pressure of gases, temperature, and use of a catalyst.
How can you investigate the effect of surface area on rate of reaction?
React marble chips with dilute hydrochloric acid and measure the rate of gas produced. Use different sizes of chips.
How can you investigate the effect of concentration on rate of reaction?
React a fixed amount of marble chips with different concentrations of hydrochloric acid and measure the rate of gas released.
How can you investigate the effect of temperature on rate of reaction?
Carry out the same reaction at different temperatures and measure how quickly a product (e.g. gas or colour change) forms.
How can you investigate the effect of a catalyst on rate of reaction?
Add a catalyst to a reaction (e.g. manganese(IV) oxide to hydrogen peroxide) and compare the speed of the reaction to one without a catalyst.
How does increasing surface area affect reaction rate (using particle theory)?
More particles are exposed, so more frequent successful collisions occur.
How does increasing concentration affect reaction rate (using particle theory)?
More particles in the same volume means more frequent collisions.
How does increasing pressure affect reaction rate (using particle theory)?
Gas particles are closer together, increasing the frequency of collisions.
How does increasing temperature affect reaction rate (using particle theory)?
Particles move faster and collide more often with more energy, increasing the rate.
What is a catalyst?
A substance that increases the reaction rate by providing an alternate reaction pathway but remains chemically unchanged at the end.
How does a catalyst work?
It provides an alternative reaction pathway with a lower activation energy.
How do you investigate the effect of surface area and concentration in the marble chips + HCl reaction?
Use marble chips of different sizes and measure gas production with a gas syringe.
Repeat with different acid concentrations.
Keep other variables constant.
How do you investigate the effect of different catalysts on hydrogen peroxide decomposition?
Add different solids (like manganese(IV) oxide, iron(III) oxide) to hydrogen peroxide solution.
Measure the volume of oxygen released over time.
What does the ⇌ symbol in a chemical equation mean?
The reaction is reversible—it can go in both forward and backward directions.
Describe the reversible reaction of hydrated copper(II) sulfate.
Heating turns blue hydrated copper(II) sulfate into white anhydrous copper(II) sulfate and water.
Adding water reverses the reaction.
Describe the reversible reaction of ammonium chloride.
Heating ammonium chloride breaks it into ammonia and hydrogen chloride gases.
Cooling recombines them into solid ammonium chloride.
