# IDH 1

In 1793, Jacques Charles launched his first balloon filled with hydrogen gas. The balloon had a volume of 27,300 Liters. What mass (in kilograms) of hydrogen gas were needed to fill the balloon at STP (standard temperature & pressure)?
At what Kelvin temperature will a sample of carbon dioxide (CO2) gas occupy at 12 liters if the same sample of CO2 occupies 8 liters at 27° C?
You are analyzing an unknown gas and find that 0.682 liters of the gas at 300 K and 760 mmHg (standard pressure) weighs exactly 2.88 g. What is the molecular weight of this gas?
4. At a winery, glucose (C6 H12 O6) in grapes undergoes fermentation (anaerobic respiration) to produce ethanol (C2 H6 O) and carbon dioxide (CO2).

How many grams of glucose are required to form 153 grams of ethanol?
How many grams of ethanol would be formed from the reaction of 0.373 kg of glucose?
5. During heavy exercise and workouts, lactic acid (C3 H6 O3), is produced and accumulates in muscles where it can cause pain and soreness (“burn”), especially under anaerobic (absence of oxygen) conditions.
How many molecules of lactic acid are there in 0.754 moles of lactic acid?
How many atoms of carbon (C) are there in 2.33 moles of lactic acid?
How many moles of lactic acid will contain 3.77 x 1021 atoms of oxygen (O).
6. Yeast make alcohol in the absence of oxygen by a process called fermentation. Complete fermentation of one mole of the sugar glucose (C6 H12 O6) will generate two moles of ethanol (C2 H6 O), two moles of carbon dioxide (CO2) gas, and two moles of the important
molecule ATP (C10 H16 N5 O13 P3), using in cellular energy transfers.
How many molecules of ATP were produced in your experiment? What is the total mass of the ATP produced?
The volume of the fermentation tank was 15 Liters, and the temperature was kept constant during the experiment at 25 degree C. Is it possible to determine the final tank pressure of the CO2 gas produced by this experiment? Will the Ideal Gas Law work here?
(c) What was the total volume of ethanol produced in this experiment?
7. Dry ice is simply frozen carbon dioxide (carbon dioxide in the solid state) and is pretty cold with a temperature of -109.3 degrees F (-78.5 degrees C). For comparison, liquid nitrogen is MUCH colder at -321 degrees Fahrenheit (-196 degrees Celsius). The carbon dioxide in dry ice will also go directly from the solid state (frozen carbon dioxide) to the gaseous state. This process is called sublimation.
You have likely seen examples of sublimation in your own freezers on food items, such as meat, that are kept for long times in the freezer, and/or not well sealed from the air. This is often called “freezer burn”, and it is caused by the sublimation of water molecules from ice crystals present on the surface of meat into the dry freezer air.
Sublimation occurs when a solid substance undergoes a phase change and becomes a vapor without first passing through a liquid phase. The ice crystals on the meat surface sublimate, and leave behind tiny cavities in the meat. These cavities are very small, but there a lots of them, and they increase the total surface area of the meat, exposing the meat tissue to air in the freezer. This excess exposure to air accelerates oxidation of fats in the meat, which causes the rancid flavors of old spoiled meat, and the classic appearance of freezer-burned meat, fish, chicken, etc.

You have 2.44 grams of dry ice in a 6.0 Liter container maintained at 31.2 C. What is the
pressure in the container after ALL the dry ice has sublimated (transformed to the gaseous state)?

You will use the Ideal Gas Law here, and you must determine which specific value to use for
the constant “R”.