Ch. 17 Flashcards
(6 cards)
How is the air pressure in a tightly sealed house affected by operating the furnace? Explain
In a tightly sealed house, the air (considered as volume) is kept constant.
By operating the furnace in that house the Temperature will increase, which also means pressure increases because they have direct relationship.
Is it possible to change both the pressure and the volume of an ideal gas without changing the average kinetic energy of its molecules? Explain.
Yes it is possible to change both of an ideal gas without changing its average KE. If the pressure and volume are changed in such a way that their product
Remains constant then the temperature will also be constant.
KE = (3/2) nRT = constant
An airport at Great elevation.
One of the highest airports in the world is located in laz Paz, Bolivia. Pilots prefer to take of in the morning or the evening when the air is quite cold. Explain.
Is is difficult for airplanes to take off at high altitude airports because the hair having low density provides less lift than the air at sea level.
When the temperature is low, the air is more dense, which then provides more lift.
An autoclave is a device used to sterilize medical instruments. It is essentially a pressure cooker that heats the instruments in water under high pressure. This ensures that the sterilization process occurs at temperatures greater than the normal boiling point of water. Explain why the autoclave produces such high temperatures.
The boiling temperature of water is directly proportional to the pressure. Since the pressure in the autoclave is greater than atmospheric pressure, the water also boils at temperature greater than 100 degree Celsius.
As the temperature of ice is increased, it changes first into a liquid then in a vapor. On the other hand, dry ice which is solid carbon dioxide, changes directly from solid into vapor as it’s temperature is increased. How might one produce liquid carbon dioxide.
In order to move from the sublimation curve, the pressure acting on the system must increase. In order to turn CO2 From solid into liquid the pressure must be increased.
Isopropyl alcohol is sometimes rubbed onto a patients arms and legs to lower their body temperature. Why is this effective?
Isopropyl alcohol has antiseptic qualities and it also evaporated easily at very low temperatures. When it evaporates, it draws heat from the body, which accounts for the lowering of the temperature of the body
