Saturated aliphatic hydrocarbons are called alkanes. They are mainly used as fuels. Depending upon their physical properties such as boiling points, density and solubility, they have many other uses. Now answer the following questions.
(i) Out of propane and butane why is propane used as a fuel for barbecue gill?
(ii) Which alkane is used as a fuel in cigarette lighters?
(iii) What is vaseline? Mention some of its uses.
Answers
"i) Barbecue is normally open. While propane and butane may be used in cold countries, but propane is preferred because it works better at low temperatures. The reason is that propane has lower boiling point (213 K), remains as gas present in the cylinder despite the cooling produced by the "Thomson effect" during the usage and therefore, ensures a constant supply of gas.
By contrast, butane becomes a liquid in the cylinder due to its higher boiling point (272.5 K) and the cooling produced by the "Joule-Thomson effect", and thus, the gas supply becomes "slower and slower" as the gas is used.
ii) Butane is used as a "fuel" in cigarette lighters because at room temperature, it is easily liquefied.
iii) Vaseline is a "mixture" of strong alkanes with low points of meting. It can prevent loss of moisture and soft lips and nail cuticles. It is also used in cosmetics and ointments."
Answer:
Here
Explanation:
Barbecue is normally open. While propane and butane may be used in cold countries, but propane is preferred because it works better at low temperatures. The reason is that propane has lower boiling point (213 K), remains as gas present in the cylinder despite the cooling produced by the "Thomson effect" during the usage and therefore, ensures a constant supply of gas.
By contrast, butane becomes a liquid in the cylinder due to its higher boiling point (272.5 K) and the cooling produced by the "Joule-Thomson effect", and thus, the gas supply becomes "slower and slower" as the gas is used.
ii) Butane is used as a "fuel" in cigarette lighters because at room temperature, it is easily liquefied.
iii) Vaseline is a "mixture" of strong alkanes with low points of meting. It can prevent loss of moisture and soft lips and nail cuticles. It is also used in cosmetics and ointments."