Rates of Reaction

Question 1

The Rate of Reaction Definition

Answer 1

The speed at which reactants are converted into products

Question 2

Collision Theory

Answer 2

Used to predict the rates of chemical reactions, particularly for gases

Question 3

Increasing Surface Area Effect

Answer 3

It reveals more of its particles to reactions so there is an increased chance of collisions between the reactant particles. Therefore there are more collisions at any given time and the rate of reaction increases

Question 4

Increasing Temperature Effect

Answer 4

increasing the temperature makes molecules move faster and have more energy and so increasing the frequency of collisions and the successful collisions

Question 5

Increasing Concentration Effect

Answer 5

If there is more of a substance in a container, there is a greater chance that more molecules will collide and speed up the rate of the reaction

Question 6

Activation Energy Definition

Answer 6

The minimum amount of energy which the reacting molecule must hold in order to undergo a specified reaction

Question 7

Planning for an Experiment

Answer 7

You need to name ALL equipment, write a method (with bossy verbs and numbered), name Ind + Dep + Con variables, do the experiment properly (following steps), and collect reliable data (repeat 2-3 times)

Question 8

Drawing and Using Graphs

Answer 8

You need to draw a graph with a line or curve of best fit, calculate the rate of a chemical reaction using the tangent to a curve, calculate the rate of a chemical reaction using data, and make predictions from graphs

Question 9

Evaluation of Data

Answer 9

Identify anomalies (something that deviates from what is standard, normal, or expected), and then suggest reasons for anomalies (human errors, lack of precision, or using inappropriate measuring equipment)

Question 10

Word Equation for Metals + Acid

Answer 10

Hydrochloric Acid and Magnesium → Salt and Hydrogen Gas

Question 11

Word Equation for Metal Carbonates + Acid

Answer 11

Hydrochloric Acid and Magnesium Carbonate → Salt + Carbon dioxide + Water

Question 12

Word Equation for Sodium Thiosulfate + Hydrochloric Acid

Answer 12

Sodium Thiosulfate + Hydrochloric Acid → Sodium Chloride + Sulfur + Sulfur Dioxide + Water

Question 13

Word Equation for Decomposition of Hydrogen Peroxide

Answer 13

Hydrogen Peroxide + Manganese Oxide → Oxygen + Water

Question 14

Measuring Rate of Gas Release

Answer 14

Experiment 1. 1) Put a measuring cylinder upside down in a bowl full of water. 2) Attach the conical flask to the cylinder by a tube and a rubber bung. 3) Pour the solution into the conical flask, replace the bung, and start the timer. 4) Record data every 15 seconds until you have at least 5 times. 5) Repeat until you have a sufficient amount of data

Question 15

Measuring Rate of Gas Release

Answer 15

Experiment 2. 1) Support a gas syringe with a stand, boss and clamp. 2) Pour solution into a conical flask, connect the gas syringe, and start the stopwatch. 3) Every 10 seconds, record the volume of gas produced. 4) Repeat steps 1 to 3 with different concentrations of the solution

Question 16

Catalyst Definition

Answer 16

A substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change

Question 17

Catalyst Example

Answer 17

Manganese Oxide (for Decomposition of Hydrogen Peroxide)

Question 18

How a Catalyst works

Answer 18

A catalyst works by providing an alternative reaction pathway to the reaction product. The rate of the reaction is increased as this alternative route has lower activation energy than the reaction route not mediated by the catalyst. The catalyst is not used up or changed in any way during this process.

Question 19

Energy Profile for a Reaction with a Catalyst

Answer 19

Lower Activation energy, a smaller curve

Question 20

Energy Profile for a Reaction without a Catalyst

Answer 20

Higher Activation energy, a bigger curve