SAC 1 Flashcards
renewable fuels
- are produced faster than used
adv - reduced CO2 emissions, can be made from organic waste
dis - lower energy content, requires land for production
non-renewable fuels
- are used faster than produced
adv - cheap, high energy content and efficiency
dis - high CO2 emissions, heavy pollutants, leaks can cause explosions
fermentation equation
C6H12O6(aq)————->2C2H5OH(aq)+2CO2(g)
complete combustion
produces CO2 and H2O
incomplete combustion
- limited oxygen
produces CO/C and H2O
exothermic
- negative △H value
- released
- high to low
endothermic
- positive △H value
- absorbed
- low to high
glucose equation
6CO2(g)+6H2O(l)———>C6H12O6(aq)+6O2(g)
cellular respiration equation
C6H12O6(aq)+6O2(g)——->6CO2(g)+6H2O(l)
% efficiency
= desired ➗ before x 100
stoichiometry ratios
N2(g)+3H2(g)——->2NH3(g)
mol1 3 2
vol 1 3 2
mL 10 30 20
density and mass equation
density = mass ➗ volume
mass = density x volume
graph (example)
x axis = various fuels
y axis = energy (kJg-1) (enthalpy)
energy in MJ, released by complete combustion of 1.00L of fuel
- m=dxv x 1000 = no° in g
- heat of combustion no° x no° of mols ➗ 1000
- answer
(to get mols no° use mass(g) ➗ molar mass
mass of (CO2) in grams produced by complete combustion of 1.00L of fuel
- ratio CO2 and ratio of 1st reactant
- multiply ratio no° of CO2 by mols of 1st reactant
- gives us CO2 no°of mols
- use m=nxM
- answer
convert celcius to kelvin
Celcius no° + 273
gas equation not at SLC
pV=nRT
R=8.31
V=L
T=K
p=kPa
n=mols
V=nRT ➗ p
T = pxV➗Rxn
at SLC (25° and 100kPa)
Vm=24.8L
n=V➗Vm
q=mc△T
q=energy (J)
m=mass of water
c=specific heat capacity (4.18)
T=temperature change
energy released from food (in kJ)
1.08g of almonds, heating 150.0g of water, temp change = 13 degrees, answer is kJg
- no° from q=mc△T➗1000
(8151➗1000=8.15) - that no°➗mass of food in g
(8.15 ➗ 1.08) - answer
(77.55kJg)
calculate energy per gram
- 1.0➗change is mass
(1.0➗1.9) - that no° x q=mc△T no° ➗ 1000
(0.526 x 20482 ➗ 1000) - answer
(10.78kJg-1)
calculate energy per mole
- 1.0➗change is mass
(1.0➗1.9) - that no° x q=mc△T no° ➗ 1000
(0.526 x 20482 ➗ 1000)=(10.78kJg-1) - multiply by molar mass
(10.78 x 74.12) - answer
(799.01 kJmol)
should produce … kJ of energy, knowing this calculate energy loss
- energy per mol number ➗ … kJ number
(799.01 ➗ 2676) - times by 100
(799.01 ➗ 2676 x 100) - answer
(29.86%)
explain structure difference
- where the OH group is attached/located, and which carbon it is attached to
- which will cause △H values to vary
gauze mat v clay triangle
- gauze mat has more metal and absorbes heat meaning less heat get to the water, therefore resulting in a lower temperature
- the clay triangle allows more heat to reach the 100ml of water
- using a clay triangle you will receive higher △H values
conclusion
- refer to aim
- refer to results
- what does it show
