rates reactions effects and that

Question 1

two ways to work out rate of reaction

Answer 1

amount of product used and made

Question 2

steeper the gradient..

Answer 2

faster rate of reaction

Question 3

how to find a tanegnt

Answer 3

draw a straight line coming off a point in the graph which is like a straight reflction of the crve idk. then connect the line to make a right angle triangle and measure the lengths of the x and y side. then divide y by x to get the rate of reaction

Question 4

why do we need tangents

Answer 4

to find the rate of a reaction ina specific point when the graph is curving

Question 5

req practical 5 (cross one)

Answer 5

put 10cm of both sodium thiosulpahte and hydrochloric acid into a concial flask and swirl until mixed, start stopwatch. put it also ontop of a black x. someone stares at the mixture until theyre unable to see the x and they record the time, this repeats with dif concentrations

Question 6

issues with req practical 5

Answer 6

everyones eyes are different sp it has to be the same -person each time

Question 7

mean RoR

Answer 7

= quantity/time

Question 8

increased sa…

Answer 8

increased rate of reaction because more pieces of the substance are surrounded by solution so can react

Question 9

increased concentration…

Answer 9

increased RoR

Question 10

repoucable experiemnt

Answer 10

you get the same sollution to ypur hypothesis regardless of if you change the apparatus, person working on it etc

Question 11

why does raising the temp increase RoR

Answer 11

gain energy which makes them more energetic heightening chances of collisions and reactions
collisions are more frequent as the speed is increased

Question 12

things that are proportional to rate

Answer 12

temp
concentration
surface area
catalyts

Question 13

pros of catalysts

Answer 13

are not used up in a reaction, cheaoper because heat isnt needed for reactions, lowers the activation energy so theres less energy needed to react and more sucessful collisions

Question 14

how do catalysts help the enviroment

Answer 14

can be reused, work instead of increasing temps which often means fossil fuels burnt. stops co2 entering the atmosphere

Question 15

what is collision theory

Answer 15

the fact that particles need enough energy to collide to cause a reaction to take place

Question 16

whats activation energy

Answer 16

the minimum amount of energy required for a reaction to take place

Question 17

whats a reversible reaction

Answer 17

when the products of a reaction can react together to form the origninal reactants

Question 18

examples of reevrsible reactions

Answer 18

• changing of litmus
  -heating anomium chlordide
• salts and water of crystalisation

Question 19

if the first reaction in a reversible reactio is exothermic..

Answer 19

the reverse of it will always be endothermic

Question 20

what is equlibrium

Answer 20

when the rate of forwards reaction equals the reverse rate of reaction

Question 21

when does equilibrium occur

Answer 21

in a closed system

Question 22

how to change amounts of reactants and products at equilibrium

Answer 22

by changing the conditions

Question 23

what was la chateliers findings

Answer 23

• when conditons are changed to a closed system at equilibrium, the position of equilibrium/reation shifts to cancel out the change
• these changes incl changes in conc, pressure or temp

Question 24

why is the principle important

Answer 24

because chemists should find the point where conditions are right to get as much product as possible

Question 25

if the forwards reaction (the creation of products) creates more gas

Answer 25

- an increase in pressure will decrease the amount of products - a decrease in pressure will increase the amount of products

Question 26

why does pressure change the amount of products

Answer 26

if you increase the pressure of the forwards reaction, the equilibrium will shift to reduce the pressure in favour of the reaction producing less gas

Question 27

if we increase the concetnration of the reactantat equilibrium

Answer 27

- the concentration of the product will be icreased until equlibrium is reached again

Question 28

if temparature is decreased at equilibrium..

Answer 28

the exothermic reaction will be increased so to increase the temparature

Question 29

if the forwards reaction (creation of products) was endothermic..

Answer 29

- if the temp decreased so would the forwards reaction as the exothermic backwards reaction would increase to raise temp - if the temp increased so would the forwards reaction

Question 30

what does pressure effect

Answer 30

reactions involving gasses

Question 31

if we increase the pressure in a reversible reaction at equilibrium

Answer 31

the equilibrium will shift to the side w the smaller number of molecules

Question 32

if both sides of the reversible reaction have the same number of molecules

Answer 32

changing pressure does ot affect the point of equilibrium

Question 33

what is dynamic equilibrium

Answer 33

when there is no effect because the forwards and backwards rate of reactions are happening at the same rate

Question 34

benefits of le chandeliers principle

Answer 34

we can predict the effect of changes to a system