Chapter I Flashcards
Outline the fermentation process that produces ethanol from glucose?
Fermentation is the process of converting glucose or other sugars into ethanol and carbon dioxide, in the presence of a catalyst. In most cases yeast. A yeast catalyst is a molecule which speeds up the reaction by making the rate of reaction increase. Yeast metabolises/concerts the sugars to alcohol when it is starved of oxygen, which is anaerobic conditions. The yeast dies when the alcohol concentration levels become too high. The temperature this reaction requires must be at room temperature which is 37 degrees, if it is too hot the enzymes will not be reactive and die.
Identify the type of bonding within the molecule of methanol?
Covalent Bonding.
What is covalent bonding?
Covalent bonding is the process of methanol molecules sharing electrons to get a full valence shell. Non metal atoms share electrons to achieve full valence shells. This also means that the molecules are saturated.
Complete combustion, Methanol.
Complete combustion occurs when there is a fair amount of oxygen in the wire. Methanol undergoes complete combustion, this means that there is a supply of oxygen in the air that can be used, this also shows that methanol which is an alcohol burns in a blue flame under the presence of oxygen, carbon dioxide, creating and producing water. Complete combustion which burns on the blue flame is hotter then the yellow/orange flame, because complete combustion releases more heat compared to incomplete combustion which doesn’t produce as much heat.
Complete combustion consequences, methanol.
Methanol which undergoes complete combustion produces one of the world most harmful gases; carbon dioxide. CO2 is the worlds number one leading cause for global warming. Carbon dioxide gathers up in the atmosphere, it allows heat to come into the earth, but instead of the heat bouncing back up and radiating back into space, a majority of the heat is trapped in the atmosphere and warms up the earths crust. Carbon dioxide is a odourless colourless tasteless gas. Signs of the earth warming up are the ice glaciers melting in the article, unpredictable weather and the rising of sea levels. One natural solution for CO2 is photosynthesis, which is when plants breathe in carbon dioxide and breathe out oxygen.
Incomplete combustion, Octane.
Incomplete combustion occurs when there is not enough oxygen supplied. Octane which combusts under incomplete combustion burns in a yellow/orange flame in the presence of carbon monoxide, also known as soot, creating/producing water. When octane burns under the yellow/orange flame in the presence of carbon, soot is produced. You can see soot is produced because when it is burning a black like smoke substance is released.
Incomplete combustion consequences, octane.
Octane which undergoes incomplete combustion produces the worlds second most contributing factor to global warming; soot, also known as carbon monoxide. CO has a direct harmful effect on humans as it is a very poisonous gas, which in some cases can lead to death. This is because if we breathe in CO it latches onto our haemoglobin cells (red blood cells) and circulates around our body, never getting off, until in the end our haemoglobin withers and dies. This interferes with the oxygen flow and circulation in our bodies, if we inhale too much, we will suffer symptoms of dizziness and lack of oxygen and in the end falling unconscious then dying. To cure this you would need to be given a pure oxygen treatment.
Explain why crude oil must be fractionally distiller before it can be used.
Crude oil requires treatment because it contains a large amount of hydrocarbons with molecules of different sizes. These are a mixture of gases, liquids and solids. Fractional distillation is a process of desperation based on the different boiling temperatures of molecules with different sizes.
Name two fractions obtained from fractional distillation tower.
Petrol and diesel oil.
Explain why fractional distillation is carried out in towers.
A tower is used because when the crude oil is heated and the hot particles rise hydrocarbons of different molecular masses have different boiling points. Larger molecules have higher boiling points. When the heated crude oil vapour enters the tower, the harder, heavier hydrocarbons with the higher boiling points condense into liquids lower in the tower, while the smaller, lighter hydrocarbons with the lower boiling points rise up the tower and condense back into a liquid at the lower temperatures near the top of the tower. The smaller hydrocarbons remain gases at room temperature and excite from the tip of the tower.
Why can alkenes be used to make polymers but alkenes cannot.
Alkenes can make polymers and alkenes cannot because they only have single carbon bonds, which means they do not have a spare bond they can use to form a monomer, but on the other hand since alkenes have double carbon bonds, the double bonds can split up and join up with another polymer, with the process of polymerisation. One bond in the double bond on the alkene molecule is broken by heat and the presence of a catalyst. Once the bond it broken, it is possible for the individual molecules to link together to form a polymer. You need high temperatures, high pressure and the presence of a catalyst. Once the bond is broken small individual alkene molecules are used a monomers to make a number of common and widely used polymers. Resulting in a single bond and spare single bond covalently bond to the next monomer to form a long chain polymer.
What does chemically inert mean?
When a type of molecule does not chemically react with anything else.
Difference between ethane and ethanol.
At room temperature, which is usually 37 degrees, during this temperature the ethane alkane is a gas, on the other hand ethanol is a liquid solution. The melting point for ethane is -183 and the burning point is -88, compared to ethane, ethanol boiling temperature is much higher and sits at 79 the melting point on the other hand is much closer to the one of ethane and sits at -117. Ethanol is completely soluble in water because the water molecules and the alcohol molecules are strongly attracted to each other. But on the other hand Ethane is not soluble in water because it does not have a strong interactive attraction force with the water molecules. This means that they will not combine; for example oil and water will not mix because the water molecules and the oil molecules do not have strong attraction forces.
What is cracking?
Cracking is the process in which long chain hydrocarbon molecules are broken down into shorter hydrocarbons by the breaking of carbon to carbon bonds. Cracking uses high temperatures and high pressure and the presence of a catalyst. Cracking is also known as pyrolysis it involved the breakdown of large alkane molecules into smaller and more useful alkenes and alkenes.
Methanol complete combustion balanced equation.
2CH3OH + 3O2 —-> 2CO2 + 4H2O
