C6a-Rates of reaction Flashcards
What is the rate of reaction?
How fast reactants turn into products
What are the 2 ways to find out the rate of reactions?
- Find out how quickly the reactants are used up
- Find out how quicly the products are made
What are the three techniques used to collect data on the rate of reactions?
- Measuring the decreasing mass of a reaction mixture
- Measuring the increasing volume of gas given off
- Measuring the decreasing light passing through a solution
How would you carry out the method of measuring the decreasing mass of a reaction mixture?
You would add marble chips to hydrochloric acid in a conical flask on top of a weighing scale and the gas that is produced would cause a decrease in mass of the solution that you would note down.
How would you carry out the method of measuring the increasing volume of a gas given off?
You would combine 2 reactants so that a gas would be given off in a conical flask with a bung and tube going out of it-magnesium and hydrochloric acid. You would then measure the volume of gas given off with a gas syringe.
How would you carry out the method of measuring the decreasing light passing through a solution?
You would place a conical flask with sodium thiosulfate and hydrochloric acid that react to This will produce a cloudy product (a insoluble solid (precipitate) suspended in liquid) over a letter x and measure the amount of time the x took to disappear or use a light sensor instead-increasing turbidity
How do you calculate the rate of reaction from a graph?
You would calculate the gradient of the tangent on a specific point of the curve.
What 5 factors affect rate of reaction?
- Surface area
- Concentration
- Temperature
- Prescence of a catalyst
- Pressure
What is collision theory?
Reacting particles need to collide with enough energy to cause a reaction to take place
When are reactions more likely to happen between reacting particles?
- When the particles collide more frequently
- When the particles collide with more energy
How does surface area affect rate of reaction?
The frequency of collisions between reacting particles increases resulting in frequency of successful collisions increasing.
How does temperature affect rate of reaction?
An increase in temperature causes particles to collide more frequently and with more energy resulting in frequency of successful collisions increasing.
How does concentration affect rate of reaction?
A higher concentration of a liquid or pressure in a gas causes the frequency of collisions between particles to increase increasing the frequency of successful collisions.
How does the prescence of catalysts affect rate of reaction?
A prescence of a catalyst lowers the activation energy needed to start a reaction by providing an alternate reaction pathway to the products-this increases the frequency of successful collisions.
Why are catalysts used in industry?
To reduce energy costs as well as being reusable-remains chemically unchanged
