Alkanes

Question 1

CRACKING
What are the conditions and products of thermal cracking?

Answer 1

Conditions: High T (700-1200K)
High P (7000 kPa)
Products: high proportion of alkenes

Question 2

CRACKING
What are the conditions and products of catalytic cracking?

Answer 2

Conditions: High T (450 C), Low pressure, and zeolite catalyst
Products: branched and cyclic alkanes
aromatic hydrocarbons

Question 3

COMBUSTION
Does complete combustion happen in short or larger alkanes?

Answer 3

Short alkanes

Question 4

COMBUSTION
Does incomplete combustion happen in short or larger alkanes?

Answer 4

Larger alkanes

Question 5

COMBUSTION
What are the conditions and products of complete combustion?

Answer 5

Condition: excess oxygen
Products: CO2 + H2O

Question 6

COMBUSTION
What is the reaction for complete combustion?

Answer 6

Reaction:
Alkane + O2 —> CO2 + H2O

Question 7

COMBUSTION
What are the conditions and products of incomplete combustion?

Answer 7

Condition: limited amount of oxygen
Products: CO (very toxic) + H2O
or C to replace CO

Question 8

COMBUSTION
What are the reactions of incomplete combustion?

Answer 8

Alkane + O2 —> CO +H2O
Alkane + O2 —> C + H2O

Question 9

REMOVING IMPURITIES
What are the conditions and products in catalytic converters?

Answer 9

Condition: Use of catalyst coated with platinum, palladium, and rhodium
Products: ‘Harmless’ carbon dioxide + nitrogen + water

Question 10

REMOVING IMPURITIES
What is the reaction for catalytic converters?

Answer 10

Reaction: Hydrocarbons + Nitrogen oxides —> CO2 + N2 + H2O

Question 11

REMOVING IMPURITIES
When burning fuels, it is important to remove ______?

Answer 11

When burning fuels, it is important to remove SULFUR

Question 12

REMOVING IMPURITIES
When burning fuels, it is important to remove sulfur because it forms _______

Answer 12

When burning fuels, it is important to remove sulfur because it forms SULFUR DIOXIDE

Question 13

REMOVING IMPURITIES
When burning fuels, the sulfur forms sulfur dioxide that can cause _________?

Answer 13

When burning fuels, the sulfur forms sulfur dioxide that can CAUSE ACID RAIN

Question 14

How are nitrogen monoxides formed?

Answer 14

When nitrogen and oxygen in the air react at high temperatures

Question 15

What is the environmental consequence of CO?

Answer 15

is toxic

Question 16

What is the environmental consequence of CO2

Answer 16

Contributes to global warming

Question 17

What is the environmental consequence of unburnt hydrocarbons?

Answer 17

formation of smog