Define
It is the average kinetic energy of the particles (atoms or molecules) in a substance.
temperature
A measure of how quickly the reactants are used up or the products are formed over time.
Reaction rate
It states that for a reaction to occur, reacting particles must collide with enough energy (activation energy) and the correct orientation.
Collision Theory
Why does increasing the temperature usually increase the rate of a chemical reaction?
Particles move faster at higher temperatures, so they collide more frequently.
It measures how much exposed area an object has.
Surface area
Average reaction rate can be solved by dividing ______ to the time.
change in quantity / change in concentration
If they collide at the wrong angle, they might just bounce off without reacting. Which condition in the theory is suitable to the statement
correct orientation
Why does powdered zinc react faster with hydrochloric acid than a single large piece of zinc?
bec. powdered zinc has more Surface area
It refers to the amount of a substance (solute) present in a certain volume or mass of a solution or mixture.
Concentration
In 10 seconds, 0.1 mol of O2 is produced in 1 liter of solution.
2H2O2→2H2O+O2
What is the rate of disappearance of H2O2?
0.02 M/s
Why do not all collisions between reactant particles lead to a reaction?
not enough energy, incorrect orientation
Ionic compounds in aqueous solutions react faster than covalent compounds, what factor affects the rate?
Nature of reactants
It is a chemical reaction where energy is given off in the form of heat.
Exothermic
If a product’s concentration goes from 0.0 mol/L to 0.5 mol/L in 10 seconds, what is its rate of appearance?
0.05mol/L/s
N2+3H2→2NH3
The rate of appearance of NH3 is 0.04 mol/L/s. What is the rate of disappearance of H2?
0.06mol/L/s
Why does increasing the temperature usually increase the rate of a chemical reaction?
Particles move faster at higher temperatures, so they collide more frequently.
It is a substance that speeds up a chemical reaction without being used up or permanently changed in the process.
catalyst
N2+3H2→2NH3
The rate of appearance of NH3 is 0.04 mol/L/s. What is the rate of disappearance of H2?
0.06mol/L/s
How does a catalyst increase reaction rate according to collision theory?
It lowers the activation energy, so more collisions have enough energy to react, increasing the rate.
A student reacts marble chips (CaCO₃) with hydrochloric acid and measures the volume of gas produced every 10 seconds.
What changes could be made to increase the rate of gas production?
Increase the temperature of the acid.
Use smaller marble chips
increase concentration of HCl