P1 3b rates of reaction

Question 1

what are the factors effecting rate of reaction?

Answer 1

surface area
concentration
temperature
catalyst

Question 2

how do you find the effect of surface area of a solid on the rate of reaction?

Answer 2

set up equipment, conical flask with dilute hydrochloric acid, a measuring cylinder filled with water in a trough (to measure displacement of water)

• add different forms of calcium carbonate chips to acid
• after a fixed amount of time record the volume of water displaced

Question 3

how do you find the effect of concentration of a solution on the rate of reaction?

Answer 3

• measure 50cm^3 of sodium thiosulphate solution into a flask
• measure 5cm^3 of dilute hydrochloric acid into a measuring cylinder
• draw a cross on paper and put it under the flask
• add acid unto the flask and start the stopwatch
• when the cross is no longer visible stop the stopwatch
• repeat using different concentrations of sodium thiosulphate

Question 4

how do you find the effect of temperature on the rate of reaction?

Answer 4

• dilute hydrochloric acid is heated to a set temperature
• add dilute hydrochloric acid into a conical flask
• add a strip of magnesium and start the stopwatch
• stop the time when the magnesium fully dissolves
• repeat using diff temps

Question 5

how do you find the effect of a catalyst on the rate of reaction?

Answer 5

Add hydrogen peroxide into a conical flask
Use a delivery tube to connect this flask to a measuring cylinder upside down in water trough
Add the catalyst manganese(IV) oxide into the conical flask and close the bung
Measure the volume of gas produced in a fixed time using the measuring cylinder
Repeat experiment without the catalyst of manganese(IV) oxide and compare results

Question 6

what is the effect of a catalyst?

Answer 6

using a catalyst lowers the activation energy, but its never used up and doesn’t effect the products of the reaction

Question 7

what will increasing the concentration do to the rate of reaction?

Answer 7

it will increase the rate of reaction because there are more particles present in the same volume, so the number of collisions increase

Question 8

what will increasing the temperature do to the rate of reaction?

Answer 8

it will increase the kinetic energy of the particles so the number of successful collisions increases

Question 9

what will increasing the surface area do to the rate of reaction?

Answer 9

more collisions per second will increase the rate of reaction, because more surface area will be exposed to the other reactant

Question 10

why are catalysts important?

Answer 10

they reduce energy costs and increase production rate

they lower the activation energy and are never altered or consumed in the reaction

Question 11

how do catalysts work?

Answer 11

catalysts work by attracting reactant molecules on to the surface, that provide alternate reaction pathway of lower energy