Paper 2- 2021 Flashcards
Name type of compound shown by formula of RCOOK
Carboxylate salt
Why is ethanol a suitable solvent when heating coconut oil with KOH?
To dissolve both oil and KOH
Meaning if fraction
Group of hydrocarbons with similar boiling points
Why CO2 absorbs IR?
C=O bond vibrate at same frequency as IR.
Name HOCH2CH2NH2? Its role?
2-aminoethanol
2-hydroxyethylamine
2-hdroxyethanamine
Acts as base/electron pair donor
How bioethanol produced
Photosynthesis: plants take in CO2 6CO2+6H2O->C6H12O6 +O2
Fermentation:Bioethanol releases CO2
C6H12O6-> 2C2H5OH+2CO2
Combustion:bioethanol burned and releases CO2
2C2H5OH+6O2-> 4CO2+6H2O
Same Co2 absorbed as released. Doesn’t consider transportation, sacrifice land that could be used for food, loss of biodiversity/habitat,
2 disadvantages of using glass beaker on tripod and gauze
Glass poorer conductor than copper
Tripod and gauze= reduces heat transfer
Why enthalpy of combustion is less exothermic than data book value?
Heat loss to surroundings
Incomplete combustion
Why benzene more thermodynamically stanle than 1,3,5 benzene ring thingy?
Electrons delocalised
Why chemists use fewer steps and higher % atom economy?
Fewer steps- better yield/ less energy used
Higher atom economy- less waste/less pollution
Why is ozone beneficial for living organisms?
Absorbs harmful uv radiation
How CFCS form Cl atoms in upper atmosphere?
C-Cl bonds broken homolytically.
How chlorine atoms catalyse decomposition of ozone?
Cl° +O3–> ClO°+ O2
ClO°+O3–> Cl°+ 2O2
Why is 1cm3 of reaction mixture added to excess NaHCO3 solution?
NaHCO3 neutralises acid and stops reaction
Why is order of reaction with respect to props one ignored?
Conc of propanone is almost constant
Conc of propanone is much larger than conc of iodine
How graph shows reaction is zero order?
Graph has straight line/ constant gradient
Rate doesn’t change as conc of iodine changes/ iodine used up at constant rate
