1)Ethanol is made by the fermentation of sugar.

(a)Suggest a temperature for carrying out the fermentation and explain your answer. -40°C(ish), ??to do with enzymes; they can't or don't work as well in other temps./controls the speed of fermentation
(b)Why is it important that air does not enter the flask? -

2)Methanol burns in oxygen to make carbon dioxide and water. The equation is exothermic, with 1452kJ/mol. of energy being released.
(a)Write a balanced equation for the combustion of methanol.
-methanol+oxygen=carbon dioxide+water
-CH3OH+O2=CO2+H2O
?(b)State how much energy (in kJ) us released when 1 mole of methanol is burned.
?(c)Calculate the amount of heat energy released on burning 4 moles of methanol.
(d)What is the molar mass of methanol?(=32) Use the value to calculate the energy release when 4g of methanol is burned. (use n=m/Mr ?)
(e)Calculate the mass of carbon dioxide produced when 16g of methanol is used. (use n=m/Mr ?)

1)(a) A suitable temperature for carrying out the fermentation would be around 30°C to 37°C. This temperature range provides optimum conditions for the enzymes involved in the fermentation process. Most enzymes have a specific range of temperatures where they work most efficiently, and this range is typically close to the temperature of the organism's natural environment. If the temperature is too low or too high, the enzyme's activity can decrease or be denatured.

(b) It is important that air does not enter the flask because oxygen can interfere with the fermentation process. In the presence of oxygen, yeast can participate in aerobic respiration, which produces less ethanol than the desired fermentation process. Additionally, any exposure to oxygen can result in contamination by unwanted microorganisms or unwanted reactions occurring, producing undesirable byproducts.

2)(a) Balanced equation for the combustion of methanol:
CH3OH + 1.5 O2 → CO2 + 2 H2O

(b) The amount of energy released when 1 mole of methanol is burned is 1452 kJ.

(c) To calculate the heat energy released from burning 4 moles of methanol:
1452 kJ/mol × 4 mol = 5808 kJ

(d) The molar mass of methanol is 32 g/mol. To calculate the energy release when 4 g of methanol is burned, use n = m / Mr:
n = 4 g / 32 g/mol = 0.125 mol
Energy released: 0.125 mol × 1452 kJ/mol = 181.5 kJ

(e) To calculate the mass of carbon dioxide produced when 16g of methanol is used, first determine the moles of methanol:
n = 16 g / 32 g/mol = 0.5 mol
Since in the balanced equation, there is a 1:1 ratio between methanol and carbon dioxide, this means 0.5 moles of CO2 are produced.
The molar mass of carbon dioxide (CO2) is 44 g/mol, thus:
mass of CO2 = 0.5 mol × 44 g/mol = 22 g

(a) The suggested temperature for carrying out the fermentation of ethanol is typically around 30-35°C. This temperature range is ideal because it allows the enzymes responsible for fermentation, specifically the yeast enzymes, to work efficiently. Enzymes are biological catalysts that speed up chemical reactions, but they have an optimal temperature range at which they perform best. In this case, the yeast enzymes responsible for converting sugar to ethanol have their optimal activity range around 30-35°C.

(b) It is important that air does not enter the flask during the fermentation process because it can introduce unwanted microorganisms or bacteria that could contaminate the fermentation process. These unwanted microorganisms or bacteria can compete with the yeast for the sugar substrate, leading to impurities in the ethanol product. Additionally, the presence of oxygen can inhibit the growth of yeast cells and slow down the fermentation process. Therefore, ensuring a controlled environment without the entry of air helps maintain the purity and efficiency of the fermentation process for ethanol production.

(a) The balanced equation for the combustion of methanol is:
2CH3OH + 3O2 → 2CO2 + 4H2O

(b) According to the given information, the combustion of 1 mole of methanol releases 1452 kJ of energy.

(c) To calculate the amount of heat energy released when 4 moles of methanol is burned, we can use the molar ratio from the balanced equation. Since the coefficient of methanol is 2 in the balanced equation, the molar ratio for methanol to heat energy is 2:1452. Thus, for 4 moles of methanol, the amount of heat energy released can be calculated as follows:
4 moles CH3OH × (1452 kJ/2 moles CH3OH) = 2904 kJ

(d) The molar mass of methanol, CH3OH, is 32 g/mol. To calculate the energy release when 4g of methanol is burned, we can use the formula n = m/Mr, where n is the number of moles, m is the mass, and Mr is the molar mass.
Number of moles of methanol = 4 g / 32 g/mol = 0.125 mol
Energy release when 0.125 mol of methanol is burned can be calculated as follows:
0.125 mol CH3OH × (1452 kJ/2 mol CH3OH) = 90.75 kJ

(e) To calculate the mass of carbon dioxide produced when 16g of methanol is used, we can use the formula n = m/Mr, where n is the number of moles, m is the mass, and Mr is the molar mass.
Number of moles of methanol = 16 g / 32 g/mol = 0.5 mol
According to the balanced equation, the molar ratio between methanol and carbon dioxide is 2:2. Therefore, the molar ratio for methanol to carbon dioxide is 2:2.
Mass of carbon dioxide produced can be calculated as follows:
0.5 mol CO2 × (44 g/mol CO2) = 22 g

1a) The suggested temperature for carrying out fermentation to produce ethanol is typically around 30-35°C. This temperature range is optimal for the activity of the enzymes involved in the fermentation process. Enzymes are biological catalysts that speed up chemical reactions, and they work best under specific temperature conditions. In the case of ethanol fermentation, the enzymes responsible for converting sugar into ethanol and carbon dioxide function most efficiently in the 30-35°C temperature range.

(b) It is important that air does not enter the flask during fermentation because the presence of oxygen can have a negative impact on the fermentation process. Oxygen acts as an inhibitor to yeast, which is the microorganism responsible for the fermentation of sugar into ethanol. When oxygen is present, the yeast will prioritize aerobic respiration (which uses oxygen) instead of anaerobic fermentation (which does not use oxygen). This can lead to lower ethanol production and reduced efficiency of the fermentation process. Therefore, to ensure that the yeast performs anaerobic fermentation and produces ethanol, it is important to create an oxygen-free environment in the flask by using an airtight seal.