Rates Of Reaction Flashcards
(18 cards)
What is the rate of a reaction?
How quickly reactants are used up or products are produced
What is the unit for rate of reaction in a reaction involving a change in mass?
g/s
What is the unit for rate of reaction in a reaction involving a change in volume?
Cm3/s
How can you measure the rate of a reaction that produces a gas?
Measure change in mass using a balance
Measure volume of gas produced using a syringe or upside down measuring cylinder
What is a precipitate?
An insoluble solid in a solution
How can you measure the rate of a reaction that produces a precipitate?
Measure how long it takes for a cross to disappear
What is the activation energy?
The minimum amount of energy colliding particles need to have before a reaction will take place
What effect does increasing concentration have on the rate of a reaction?
Increases
Why does increasing concentration have this effect?
More reactant particles in the same volume lead to more frequent collisions
What effect does increasing pressure have on the rate of reaction?
Increases
Why does increasing pressure have this effect?
Less space between particles means more frequent collisions
What effect does increasing surface area have on the rate of a reaction?
Increases
Why does an increasing surface area have this effect?
More reactant particles are exposed and able to collide, leading to more frequent collisions
What effect does increasing temp have on the rate of reaction?
Increases
Why does increasing temp have this effect?
Particles move faster, leading to more frequent collisions- particles have the same activation energy, so more collisions result in a reaction
What is a catalyst?
Speeds up the rate of reaction without being used up
How do catalysts increase the rate of reaction?
Lower the activation energy of the reaction, so more collisions result in a reaction
Silver chloride is an insoluble salt that can be made into the following reaction. Suggest how the rate of this reaction could be measured
AgNo3(Aq) + NaCl(aq) =
NaNo3(aq) + AgCl(s)
One way of measuring the rate of a reaction is to look at the rate of production of silver chloride precipitate. This could be measured by placing the beaker with the reacting solution on a piece of white paper with a black cross printed on it, and measuring the time taken for the cross to disappear.
