Rates of Reaction

Question 1

what does the steeper line on a graph show?

Answer 1

the faster rate of reaction, become flat in the least amount of time

Question 2

what is collision theory?

Answer 2

The more collisions there are the faster the reaction becomes, particles must collide with sufficient energy.

Question 3

what does the rate of reaction depend on?

Answer 3

Temperature, concentration, pressure, surface area, catalyst

Question 4

what happens when the temperature is increased?

Answer 4

the particles move faster, colliding more frequently with more energy.

Question 5

What happens when there is a higher concentration or pressure?

Answer 5

more particles knocking into eachother in same volume, same number of particles occupies a smaller space for pressure increase.

Question 6

what do catalysts do?

Answer 6

decrease activation energy by providing an alternative reaction pathway with lower activation energy

Question 7

whats the equation for rate of reaction?

Answer 7

amount of reactant used or amount of product formed/ time

Question 8

How can you record the visual change in a reaction through an initial solution thats transparent to one that is opaque?

Answer 8

cross at bottom of flask
measure how long it takes to disappear
different people may have different eye sights

Question 9

how do you measure a change in mass?

Answer 9

use a mass balance
as gas is released through flask the mass decreases
most accurate of 3 methods as mass balance is very accurate
gas let off into room could be safety issue

Question 10

How to work out the volume of gas given off?

Answer 10

use a gas syringe
quite accurate

Question 11

how do you do an investigation for effect of concentration on the rate of reaction?

Answer 11

add set volume of dilute HCI in conical flask and place onto mass balance
add magnisum ribbon to acid and plug flask with cotton wool
start stop watch and record mass on balance
take readings of mass at regular intervals
repeat with more concentration acid

Question 12

What does an experiment of sodium thiosulfate and HCI to produce a cloudy precipitate look like?

Answer 12

form yellow precipitate
add set volume of dilute sodium thiosulfate
place flask on paper with black cross on it
add dilute HCI and start stop watch
now watch cross disappear

Question 13

what is happening at equilibirum?

Answer 13

both reactions are happening but there is no overall effect, only happens in a closed system.

Question 14

what happens if equilibrium lies to the right?

Answer 14

concentration of products is greater than that of reactants

Question 15

what happens if equilibrium lies to the left?

Answer 15

concentration of reactants is greater than that of products

Question 16

what can change the position of equilibrium?

Answer 16

temperature, pressure, concentration

Question 17

what is le chatelier’s principle?

Answer 17

if you change the conditions of a reversible reaction at equilibrium the system will try to counteract that change.

Question 18

what happens to equilibrium if you decrease temperature?

Answer 18

equilibrium move to the exothermic direction to produce more heat

Question 19

what happens to equilibrium if you increase pressure?

Answer 19

equilibrium tries to reduce it, moves to the direction where there are fewer molecules of gas