Rates of Reaction - not finished

how can you tell that a chemical reaction has taken place?

a change in mass, heat being taken in or given out, bubbles are formed or there is a change in colour

define reactants

substances used to start a chemical reaction

define product

substances produced in a chemical reaction

define variable

any factor that can be controlled, changed or measured during an investigation

define collision theory

this means that for a reaction to occur reactants must collide

what are some of the most common variables in a reaction

temperature, surface area, concentration and catalysts

how does temperature affect a rate of reaction

it creates more heat energy in the substance and the particles will have more energy to move around so the particles have more opportunity to collide therefore increasing the rate of reactions

how does concentration affect a rate of reaction

a concentrated solution contains more solute than a diluted one so therefore there are particles with more collision opportunity to increase rate of reaction

what are the two ways to increase the concentration in an investigation

using a more concentrated solution - more solute in the same volume of solvent and using the same solute particles in a lower volume of solvent

define catalyst

a chemical that speeds up a reaction

define enzyme

a biochemical catalyst found in our bodies

how does a catalyst affect a rate of reaction

catalysts speed up a reaction without