# Rates of Reactions

HideShow resource information
• Created by: Heather
• Created on: 10-05-14 10:03
What is one way of measuring a rate of reaction using weighing scales?
Firstly, you weigh the reactants used in the reaction as well as the conical flask they are in on the scales and record. Leave the conical flask with reactants on the scale and whjen they react, record the mass at time intervals- how fast mass lost,
1 of 17
What is the second way of measuring a rate of reaction when gas is release?
A gas syringe which is attached to the top of the conical flask with the reactants in and the volume of gas produced is recorded at time intervals to tell us how fast it was being produced,
2 of 17
What is the last way to measure rates of reactions when the reactions produced an insolube salt?
The conical flask is placed on a white sheet of paper with a black cross in the centre of the flask. The time is recorded for how long it takes for the cross to disappear. The shorter the time, the faster the rate of the reaction
3 of 17
What are the four main factors that affect the rate of gthe reaction?
-Temperature, -Surface area, -Concentration of solution or pressure of gas, -Presence of catalyst,
4 of 17
What is the activation energy?
The smallest amount of energy that particles need before they can react,
5 of 17
How does temperature what are the two ways the rate of the reaction increases?
Particles collide more often adn they collide with more enrgy,
6 of 17
How does the remperature affect the rate of reaction explained?
As the temperature reises, the particles in the mixture move around more quickly so they collide more frequently so faster rare. Also,they have more energy so more particles have enough enrgy to react,
7 of 17
How does the size of the solid in reactions affect the rate of reaction?
As there is more surface exposed for reactants to react on so reactions take place more frequently so faster,
8 of 17
How does the concentration or pressure affect the rate of gthe reaction?
Increasing the concentration increases the number of reactants in the colution as there are more reactants to collide with. Increasing pressure means more particles together so more likely to collide,
9 of 17
What is a catalyst?
A catalyst speeds up the rate of a reacgtion without being chemically used up itself,
10 of 17
How do catalysts speed up the rate of reaction?
They decrease the amount of activation energy needed by the reactants so more likely to react as it provides a surface for reactants to react on,
11 of 17
What is an exothermic reaction?
When reactions transfer energy from the reacting reactants to their surrounding which often heats it up,
12 of 17
What are three examples of an exothermic reaction?
-Combustion, -Neutralisation reactions, -Respiration, -Hand warmers,
13 of 17
what is an endothermic reaction?
When reactions transfer energy from the surroundings to the reacting chemicals which causes surrounding temperatures to drop,
14 of 17
what are three examples of an endothermic reaction?
-Thermal decomposition, -Sherbets, -Cooling injury pack,
15 of 17
Energy can't be _ _ _ _ _ _ _ or _ _ _ _ _ _ _ _ _
created or destroyed
16 of 17
In reverislbe reactions, how much energy is produced in both directions?
They produce equal amounts of energy as none is created or destroyed just transferred,
17 of 17

## Other cards in this set

### Card 2

#### Front

What is the second way of measuring a rate of reaction when gas is release?

#### Back

A gas syringe which is attached to the top of the conical flask with the reactants in and the volume of gas produced is recorded at time intervals to tell us how fast it was being produced,

### Card 3

#### Front

What is the last way to measure rates of reactions when the reactions produced an insolube salt?

### Card 4

#### Front

What are the four main factors that affect the rate of gthe reaction?

### Card 5

#### Front

What is the activation energy?