DF 1 and general knowledge Flashcards
what is crude oil and where is it from
- crude oil is a fossil fuel
- formed from the remains of dead organisms from millions of years ago trapped underground
what is crude oil made of
- a mixture of hydrocarbons
what are alkanes and their general formula
-saturated hydro carbons, so there are only single bonds between atoms and they are unreactive
-Cn H2n+2
name the hydrocarbon prefixes from 1-10 carbons
Meth..
Eth..
Prop..
But..
Pent..
Hex..
Hept..
Oct..
Non..
Dec..
What is the difference between the structural formula and the molecular formula
the molecular formula is is the condensed version of the structural formula
What is the difference between the structural formula and the molecular formula
the molecular formula is is the condensed version of the structural formula
explain the trend that comes with the increasing amount of carbons in a hydrocarbon
as the amount of carbons increase, the molecule gets bigger and the larger the amount of intermolecular forces, the state also changes from gas to liquid to solid
draw the skeletal structure of heptane
/\/\/\
how would you test for an alkene
alkenes would decolourise bromine water when reacting with it
what happens to molecules with longer chains
Longer chain mol. not very reactive or flammable. due to strong intermol. forces
cracked to produce a mixture of alkanes and alkenes
what is the general formula for alkenes
Cn H2n
what are the molecular shapes and bond angles of alkanes and alkenes
alkanes- tetrahedral 109.5
alkenes- trigonal planar 120
what is the general formula of an alkyl
Cn H2n+1
what is the letter formula that is present in every:
-carboxyl
-ester
-amide
-COOH
-COO
-CO
how to find ^H
H products - H reactants
difference between endothermic and exothermic reactions
bonds are being broken during endothermic reactions, so the system takes in energy from surroundings
bonds are being formed in exothermic reactions, the system releases energy into the surroundings
what are the standard conditions when comparing reactions
Temperature - 298K
Pressure - 100 kPa
Concentration - 1 mol/dm -3
define absolute 0
temperature of 0K or -273’C
define the standard enthalpy change of combustion
enthalpy change when one mole of substance is burnt completely with oxygen under standard conditions
define the standard enthalpy change of formation
enthalpy change when one mole of substance is made from its elements with both the elements and the substance in standard states
define the standard enthalpy change of neutralisation
enthalpy change when one mole of hydrogen ions react with one mole of hydroxide ions to form one mole of water under standard conditions
how to calculate energy changes
mass of water x specific heat capacity x temperature change
