chapter 12 Flashcards
alkanes
-saturated hydrocarbon, no double bond
properties of hydrocarbons
-soze of molecule
-boiling point
-volatility, tendency to turn into a gas
-viscosity, resistence to flow, thickness
-flammability
fractional distillation
- engineers seperate out crude oil into hydrocarbons with similar boiling points, called fractions
-crude oil is heated and fed into the near bottom of the container
-hydrocarbons with the smallest molecules have the lowest boiling points, they are collected at the cool top of the column
-hydrocarbons with the longer chain of molecules have higher boiling pints, they cool to form very thick liquid or solids at room temp at the bottom on the column
sulfure dioxides and oxides of nitrogen, cause…
acid rain
and increase in carbon dioxide may result in…
climate change and solid particles cause global dimming
advanatges of diesel and other biofuels
-less harmful to animals and plants if spily than crude oil
-makes less sulfur dioxide
-biofuels will become cheaper to use, renewable
-carbon nuetral
disadvanatages of biofuels
-large areas of farmland are used to produce biofuels instead of food could pose problems
-could results in famin in poorer countries if the price of staple food crops rises ad demand overtakes supply
-people are worried about endangered species because of the destruction of thier habitats cleared to grow biofuel crops
ethanol as a biofuel
-produced from a dilute solution of ethanol obtained by the fermenattion of plant materials between 20 - 35 degrees
-enzymes in yeast are natural catalysts, and this is a batch porcess, unlike ethene sugar is a renewable resource
how is ethanol made
-reacting ethene with steam
-phosphoric acid is used as a catalyst to increase the rate of reaction
incomplete combustion
-happens when the supply of air/oxygen is poor
-products: carbon + carbon monoxide + water
-alkenes burn with smokier flames
