Questions Corrections 2023 Flashcards
The reaction between hydrogen and chlorine is exothermic
Explain why this reaction releases energy to the surroundings
Energy is needed to break bonds and energy is released when bonds form
The energy released is greater than the energy needed
Name an indicator and the colour change that will occur when acid from a burette is added to the alkali
Methyl Orange
From yellow to red
Give the formula of the ion that makes a solution alkaline
OH(minus)
Explain how oxygen was produced from water during the electrolysis os this aqueous solution
Water molecules break down
To produce H+ and OH- ions
So OH- ions are attracted to positive electrode
OH- ions are oxidised to give oxygen
Two observations that could be made when barium reacts with hydrochloric acid
Forms a colourless solution
Effervescence
Suggest 2 reasons why are nano particles used instead of fine particles
Less needed for the same effect
Have a higher surface area to volume ratio
Describe a test for the double carbon-carbon bond in cycloalkene
molecules
Add bromine water
Changes from brown/orange to colourless
Three advantages of hydrogen fuel cells instead of using rechargeable cells
No toxic chemicals to dispose of at the end of the cells life
Takes less time to refuel
travel further before refuelling
Why can’t sodium chloride solution not be used as the electrolyte to produce sodium metal
Hydrogen would be produced instead of sodium
As sodium is more reactive than hydrogen
Two reasons why burning wood for fuel is more sustainable than using natural gas
Wood is renewable
Wood is carbon neutral it produces same amount of CO2 that the trees absorbed
Explain the process by which carbon monoxide can be produced when methane is burned
Not enough oxygen
So incomplete combustion
Why would electrolysis not take place when using solid zinc chloride
Solid zinc chloride does not conduct electricity
As ions cannot move in the solid is needs to be in solution or molten
