Consider the compounds A to E in the table on the right and answer the questions below. (a) Why can all of these compounds be described as hydrocarbons? (b) Give the IUPAC names for any three of these compounds. (c) Which of the five compounds (i) is used in oxyacetylene cutting and welding of metals, (ii) is the main component of natural gas, (iii) is a component of LPG (liquefied petroleum gas)? (iv) is an alkene, (d) Each of these compounds burns in excess oxygen to produce the same two products. Give the names or formulae of these two products. (e) Compound E is aromatic. Explain aromatic in terms of chemical structure. Would you expect compound E to have a high octane number? Explain your answer.

Leaving Cert Chemistry Organic Chemistry: Consider the compounds A to E in

Consider the compounds A to E in the table on the right and answer the questions below - Leaving Cert Chemistry - Question 6 - 2015

Question 6

Consider the compounds A to E in the table on the right and answer the questions below. (a) Why can all of these compounds be described as hydrocarbons? (b) Give ... show full transcript

Worked Solution & Example Answer:Consider the compounds A to E in the table on the right and answer the questions below - Leaving Cert Chemistry - Question 6 - 2015

Step 1

Why can all of these compounds be described as hydrocarbons?

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Answer

Hydrocarbons are defined as organic compounds that contain only carbon (C) and hydrogen (H) atoms. All the compounds A to E can be classified as hydrocarbons because they exclusively consist of carbon and hydrogen in their molecular structures.

Step 2

Give the IUPAC names for any three of these compounds.

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Answer

Compound A: Methane (C(_1)H(_4))
Compound C: Propane (C(_3)H(_8))
Compound D: Methylbenzene, also known as Toluene (C(_7)H(_8))

Step 3

Which of the five compounds

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Answer

(i) is used in oxyacetylene cutting and welding of metals:
Answer: Compound C: Acetylene (C(_2)H(_2))
(ii) is the main component of natural gas:
Answer: Compound A: Methane (C(_1)H(_4))
(iii) is a component of LPG (liquefied petroleum gas):
Answer: Compound D: Propane (C(_3)H(_8))
(iv) is an alkene:
Answer: Compound B: Ethylene (C(_2)H(_4))

Step 4

Give the names or formulae of these two products.

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Answer

The two products formed when these compounds burn in excess oxygen are:

Water (H(_2)O)
Carbon Dioxide (CO(_2))

Step 5

Explain aromatic in terms of chemical structure. Would you expect compound E to have a high octane number? Explain your answer.

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Answer

Aromatic compounds are characterized by the presence of a benzene ring, which is a cyclic structure with delocalized π (pi) electrons, providing stability and resonance.
Given that compound E contains a benzene ring and has a high degree of unsaturation, it is indeed expected to have a high octane number due to the stability and favorable combustion properties of aromatic compounds.

Consider the compounds A to E in the table on the right and answer the questions below - Leaving Cert Chemistry - Question 6 - 2015

Worked Solution & Example Answer:Consider the compounds A to E in the table on the right and answer the questions below - Leaving Cert Chemistry - Question 6 - 2015

Why can all of these compounds be described as hydrocarbons?

Give the IUPAC names for any three of these compounds.

Which of the five compounds

Give the names or formulae of these two products.

Explain aromatic in terms of chemical structure. Would you expect compound E to have a high octane number? Explain your answer.

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