Quiz 1 Flashcards
Describe how the rate of reaction change from the start of the reaction until its end
Very high at the beginning
Slows as the reaction progresses
Becomes zero at the end
Describe how the surface area of a solid can be increased
By cutting it up or using smaller pieces
Define catalyst
A substance which increases the rate of a reaction but is not used up in that reaction
State the effect of increasing the surface area of a solid on the rate of reaction
It increases the rate
State the effect of increasing the concentration of a solution on the rate of reaction
It increases the rate
In a reaction, a student calculates the number of moles of product that are produced in a certain amount of time. State the unit they could use for the rate of the reaction
mol/s
In a chemical reaction, the mass of the reactant changes. State an equation that could be used to calculate the rate of reaction
Rate of reaction= change in mass of reactant/time
Explain the effect of using a catalyst on the rate of reaction
They provide a different pathway for the reaction which has a lower activation energy
More particles have the activation energy
More particles can collide successfully
Rate of reaction increases
State the effect of increasing temperature on the rate of reaction
It increases the rate
Explain why increasing the surface area of a solid increases the rate of reaction
More particles are available to collide
Therefore more frequent collisions between the reactants
In a chemical reaction, a gas is produced. State an equation that could be used to calculate the rate of reaction
Rate of reaction= change in volume of product/time
Name the 2 main units for the rate of reaction
g/s or cm3/s
Explain why increasing the pressure of a gas increases the rate of reaction
There is less space between particles
Therefore more frequent collisions
Explain how the unit for the rate of a reaction can be established from a rate graph
Rate of reaction= y unit/x unit
Explain why increasing the concentration of a solution increases the rate of reaction
Higher concentration means more particles in a given volume
Therefore more frequent collisions between the reactants
Explain why a reactions rate decreases with time
Overtime, the reactant turns to product
There is less reactant available
There are less frequent collisions as time goes on
State the effect of increasing the pressure of a gas on the rate of reaction
It increases the rate
Explain how the rate of a reaction at a specific time can be calculated using a graph
By drawing a tangent to the curve and calculating its gradient
Explain why increasing the temperature of a reaction increases the rate of reaction
Increases the speed at which particles move, resulting in more frequent collisions
It also increases the number of particles which have the activation energy therefore more collisions result in a reaction
Define activation energy
The amount of energy a particle needs before it will be able to react when it collides with another particle
What are the 4 factors that affect rate of reaction
tempreature, concentraction/pressure, catalyst and surface area
