C6

Question 1

what factors affect the rate of reaction?

Answer 1

-temperature
-the concentration of a solution or the pressure of gas
-surface area
-the presence of a catalyst

Question 2

what is the collision theory?

Answer 2

Particle theory states that chemical reactions occur only when the reactant particles collide with sufficient energy to react. The minimum amount of energy needed is called the activation energy.

Question 3

rate of reaction graphs

Answer 3

amount or product formed
time

Question 4

rate of reaction formula

Answer 4

rate of reaction =

amount of reactant used or amount of product formed
——————————————————————
time

Question 5

what are the 3 ways to measure the rate of reaction?

Answer 5

1) precipitation and colour change
2) change in mass -usually gas given off-
3) the volume of gas given off

Question 6

measuring rates of reaction practical:

Answer 6

clear to cloudy- X underneath, how long can you see it

Using a measuring cylinder, add 50 cm3 of dilute sodium thiosulfate solution to a conical flask.
Place the conical flask on a piece of paper with a black cross drawn on it.
Using a different measuring cylinder, add 10 cm3 of dilute hydrochloric acid to the conical flask. Immediately swirl the flask to mix its contents, and start a stop clock.
Look down through the reaction mixture. When the cross can no longer be seen, record the time on the stop clock.
Measure and record the temperature of the reaction mixture, and clean the apparatus as directed by a teacher.
Repeat steps 1 to 5 with different starting temperatures of sodium thiosulfate solution.

Question 7

how to find reaction rates from graphs:

Answer 7

change in concentration/change in time
than find the mean

Question 8

how to find the reaction rate at a particular point on a graph:

Answer 8

-draw a tangent
-calculate the gradient of the tangent

Question 9

reversible reactions will reach….

Answer 9

..Equilibrium

Question 10

why can the position of equilibrium be on the right of left?

Answer 10

when a reactions at equilibrium it doesn’t mean the amounts of reactants and products are equal

if the equilibrium lies to the right the concentration of products is greater than that of the reactants

if the equilibrium lies to the left the concentration of reactants is greater than that of the products

Question 11

reversible reactions can be…

Answer 11

…Endothermic and Exothermic

Question 12

what is le chateliers principle?

Answer 12

Le Chatelier’s Principle is a chemical principle that allows us to predict how the position of an equilibrium will shift in response to a change in its conditions. The principle states that: If the conditions of an equilibrium are changed, the equilibrium will shift its position in order to counteract that change.

Question 13

reversible reactions try to counteract changes….

Answer 13

….such as changes to the temperature pressure or concentration.