Give two reasons why boilers are designed to ensure
complete combustion
1. Prevents release of toxic CO
2. More energy efficient (releases more energy on
combustion)
Suggest how an engineer or a chemist could demonstrate
that the combustion of hexane in a faulty boiler was
incomplete.
Detect CO gas
Suggest why the product Z (alkene) has more commercial
value than hexane.
Can be made into polymers (or alcohols etc)
Give one reason why this atom economy of less than
100% is an important consideration for the commercial
success of this process and predict how a chemical
company would maximise profits from this process.
, 1. Because expensive chlorine is not incorporated into
desired product
2. Raise money by selling HCl
Gas oil (diesel), kerosine (paraffin), mineral oil (lubricating
oil) and petrol (gasoline) are four of the five fractions
obtained by the fractional distillation of crude oil within
the temperature range 40–400 °C.
Identify the missing fraction and state the order in which
the five fractions are removed as the fractionating column
is ascended.
Missing fraction = naphtha
1. Mineral oil (lubricating oil
2. Gas oil (diesel)
3. Kerosene (paraffin)
4. Naphtha
5. Petrol (gasoline)
Give two reasons why the fractions collect at different
levels in the fractionating column.
1. Temperature of column decreases upwards
2. Larger molecules condense at higher temperatures
Thermal cracking of large hydrocarbon molecules is used
, to produce alkenes. State the type of mechanism involved
in this process.
(free) radical / homolytic fission
Explain why it is desirable that none of the sulphur-containing
impurities naturally found in crude oil are present in petroleum
fractions.
1. Sulphur (containing impurities) burn to form SO2
2. Leading to acid rain
The pollutant gas NO is found in the exhaust gases from petrol
engines. Explain why NO is formed in petrol engines but is not
readily formed when petrol burns in the open air.
1. NO formed by reaction between N2 and O2 from the air
(1) OR
2. N2 +O2 →2NO
3. High combustion temperature or spark in engine
4. Provides sufficient heat energy to break N =N (meant to
be 3 lines)
complete combustion
1. Prevents release of toxic CO
2. More energy efficient (releases more energy on
combustion)
Suggest how an engineer or a chemist could demonstrate
that the combustion of hexane in a faulty boiler was
incomplete.
Detect CO gas
Suggest why the product Z (alkene) has more commercial
value than hexane.
Can be made into polymers (or alcohols etc)
Give one reason why this atom economy of less than
100% is an important consideration for the commercial
success of this process and predict how a chemical
company would maximise profits from this process.
, 1. Because expensive chlorine is not incorporated into
desired product
2. Raise money by selling HCl
Gas oil (diesel), kerosine (paraffin), mineral oil (lubricating
oil) and petrol (gasoline) are four of the five fractions
obtained by the fractional distillation of crude oil within
the temperature range 40–400 °C.
Identify the missing fraction and state the order in which
the five fractions are removed as the fractionating column
is ascended.
Missing fraction = naphtha
1. Mineral oil (lubricating oil
2. Gas oil (diesel)
3. Kerosene (paraffin)
4. Naphtha
5. Petrol (gasoline)
Give two reasons why the fractions collect at different
levels in the fractionating column.
1. Temperature of column decreases upwards
2. Larger molecules condense at higher temperatures
Thermal cracking of large hydrocarbon molecules is used
, to produce alkenes. State the type of mechanism involved
in this process.
(free) radical / homolytic fission
Explain why it is desirable that none of the sulphur-containing
impurities naturally found in crude oil are present in petroleum
fractions.
1. Sulphur (containing impurities) burn to form SO2
2. Leading to acid rain
The pollutant gas NO is found in the exhaust gases from petrol
engines. Explain why NO is formed in petrol engines but is not
readily formed when petrol burns in the open air.
1. NO formed by reaction between N2 and O2 from the air
(1) OR
2. N2 +O2 →2NO
3. High combustion temperature or spark in engine
4. Provides sufficient heat energy to break N =N (meant to
be 3 lines)
