REACTIONS

Question 1

collision theory

Answer 1

for a collision to be successful, particles must
* collide in the correct orientation.
* the colliding particles must also have the minimum ke required to initiate the reaction aka activation energy

Question 2

activation energy

Answer 2

• minimum amount of energy colliding particles need for a collision to be successful, and for a reaction to occur.

or

• minimum energy barrier reactant particles must overcome in order to react.

Question 3

how to increase ror

Answer 3

• increase sa (decrease particle size, powder type sh)
• increase gas pressure
• increase conc.
• increase temperature
• add catalyst (usually some transition metal)

Question 4

how does a catalyst speed up a reaction

Answer 4

by providing an alt reaction pathway with a lower activation energy

Question 5

what can effect the vol of gas formed or whatever product it is

Answer 5

• amt (mol) of limiting reactant only
• rest will only effect how fast it is formed, making the graph steeper.

Question 6

how to detect if reaction is taking place?

Answer 6

• change in color (if halogens present)
• disappearance of cross (indicates formation of insoluble precipitate)
• effervescence

Question 7

how to measure ror if gas produced

Answer 7

gas syringe

Question 8

how to measure ror if gas produced is heavy

Answer 8

change in mass

Question 9

how to measure ror if gas produced is insoluble in water

Answer 9

water disaplacement method

Question 10

factors that affect equilibrium

Answer 10

temp↑, shift to endothermic side

pressure↑, shift to side with fewer gas moles

conc of reactants ↑, shift to product side
conc of products ↑, shift to reactant side

catalyst ↑ rate of fw reaction and bw reaction in the same manner. by using a catalyst, equilibrium will be achieved faster, no effect on amt/vol/mass of product

Question 11

what happens in haber process

Answer 11

• more temp, more reactants formed, low temp, more product formed but ror very less. so use optimum temp so that ror also good and product yield also high
• high pressure used because high pressure cause to shift to side with low gas moles so more products formed
  N2+3H2=2NH3
  4 vs 2
• finely divided Fe used to speed up reaction. finely divided bc high sa = faster ror and Fe is a transition metal that is used as a catalyst to achieve equilibrium faster.

Question 12

Concept of equilibrium

Answer 12

when rate of fw = rate of bw reaction

reactants and products may or may not be same
but they will be constant as they are produced at the same rate

Question 13

le chatliers principle

Answer 13

when a system is in equilibrium, and the equilibrium is disturbed, then the system will want to undo the effect of the change to go back into equilibrium