rate of reaction

Question 1

equation for rate of reaction

Answer 1

amount of reactants used or product formed / time

Question 2

rate of reaction depends on 2 things

Answer 2

• frequency of collisions
• energy with which the particles collide

Question 3

what is activation energy

Answer 3

the minimum energy needed for particles to react ( move/ collide)

Question 4

factors affecting rate

Answer 4

• temperature
• concentration/pressure
• surface area
• catalyst

Question 5

why does increasing the temperature increase the rate of reaction

Answer 5

• increased kinetic energy of particles, increasing energy of collisions so more successful collisions and more collisions overall

Question 6

why does increasing the concentration increase the rate

Answer 6

if a solution is made more concentrated, there are more particles of reactant in the same unit of volume, meaning more collisions, and more successful collisions

Question 7

why does increasing the pressure increases rate

Answer 7

for gases

it means the particles are more crowded, because there is a bigger density and a larger force being exerted on them so the frequency o collisions between particles will increase

Question 8

why does increasing the surface area increase the rate of reaction

Answer 8

more area is exposed, and the particles around will have more surface to collide with so frequency of collisions increases

Question 9

a catalyst is

Answer 9

a substance that does not get used up or chemically changed while increasing the rate of reaction

Question 10

how do you measure the volume of gas given off ( changing surface area ) (reacting different sized marble chips with hydrochloric acid)

Answer 10

• Have a beaker filled with hydrochloric acid
• At the mouth of the beaker there should be a syringe to catch and measure the volume of CO2 that will be produced
• Have three different sizes of marble chips, ( need to add up to the same mass)
• Add one of the sizes of the marble chips inside and immediately close the top off with the syringe ( make sure syringe was set at 0, and it is straight up so the gas can pass easily through/in it)
• Measure the time it takes for marble chips to fully react
  Repeat with other sizes of chips.

Question 11

How does changing temperature affect the rate of reaction between hydrochloric acid & magnesium ribbon) investigation

Answer 11

• Gather apparatus and set up your water bath with 100ml of water at a temperature of 5ºC
• Measure 25ml of hydrochloric acid and put it in your water bath until it reaches a temp of 5º
• Once acid has been removed from waterbath, add magnesium ribbon and weight the conical flask immediately
• Start your stopwatch and at 2 mins weigh the solution again and record data
  Repeat with temps of 15, 25,35º C