C6 Flashcards
what is an activation energy?
the minimum amount of energy to make particles react. (or for a reaction to take place)
what is the rate of reactions determined by?
temps, surface area, concentration (of solution) or pressure (of a gas) and the presents of catalysts.
what are the three ways to measure the rate of a reaction?
- precipitation and colour change
- change in mass
- volume of gas given off
how do you calculate the rate of a reaction?
amount of reactant used or amount of products formed / time
give an example of an experiment for each ‘way to measure the rate of a reaction’
(precipitation and colour change)- draw an X on some paper and place it under the beaker. Measure how long it takes for the X to disappear as solution goes cloudy.
(change in mass)- measure change in mass. carry out the experiment on a measuring scale. the quicker the change in mass the faster the reaction.
(volume of gas given off)- attach gas syringe and carry out reaction. the more gas given off during a given time interval, the faster the reaction.
what does it mean when a reactions at a rate of equilibrium?
when the concentration of the reaction and the products are the same and have reached a balance so won’t change.
what was le Chatelier’s principle?
the idea that if you change the conditions of a reversible reaction at equilibrium, the system will try to counteract that change.
