Rates of reactions/ energy transfer in chemical reactions Flashcards
What is the law of conservation of mass
That when a chemical reaction occurs the total mass of the reactants is always equal to the mass of the products
What factors effect rates of reaction
Types of reactants
Particle size
Concentration
Temperature
Catalysts
What is a catalyst
A substance that alters the rate of a chemical reaction but is not used up in the reaction
Describe an exothermic reaction
This is a reaction where energy is transferred from the chemicals to the surroundings. The temperature of the reaction mixture usually rises
Gives out hear
What is an endothermic reaction
An endothermic reaction is one that takes in heat
What are reactants
Substances that start a chemical reaction
What are products
Substances that are formed from the chemical reaction
How does type of reactants affect rates of reaction
Increasing the concentration of one or more reactants will often increase the rate of reaction.
How does particle size affect rates of reaction
The smaller the particle size the faster the reaction
How does concentration affect rates of reaction
The higher the concentration of reactants, the faster the rate of a reaction will be
How does temperature affect rates of reaction
Increasing the temperature increases the average speed of the reactant molecules
Name an everday example of exothermic reactions
Hand warmers
Name an everday example of endothermic reactions
Photosynthesis, Cooking an egg
