Chapter 4: Textbook Flashcards
How is force affected when exerted on a larger area?
The pressure is lower
How is force affected when exerted on a smaller area?
The pressure is higher
What is pressure?
The force per unit area
What kind of force is measured by gases?
The force exerted by moving molecules as they collide with objects in the path, particularly the walls of their container
What is the unit for pressure?
(Pa) Pascals
What is force measured in?
(N) Newtons
What does one Pascal measure?
The force of 1 N on an area of 1 Meter squared. 1 Pa = 1 N/m2
What is atmospheric pressure and the pressure of other gasses measured in?
Kilopascals (kPa)
What is a kPa?
1000 Pa or 1kN/m2 exactly
What is atmospheric pressure?
The force per unit area exerted by air on all objects
What is the atmospheric pressure at sea level?
About 101 kPa or
101.325 kPa exactly
What basis do scientists use to describe one standard atmosphere ( 1 atm)?
The atmospheric pressure at sea level 101.325 kPa
What were the previous standards for work with gases?
A temperature of 0 and a pressure of 1 atm/101.325 kPa
What conditions were known as Standard Temperature and Pressure (STP)?
0 degrees and 1 atm/101.325 kPa
What is the new standard for reporting the properties of substances called?
Standard Ambient Temperature and Pressure (SATP)
What are the definitions of Standard Ambient Temperature and Pressure (SATP)?
25 degrees and 100 kPa
How did Evangelista Torricelli accidentally invent a way for measuring atmospheric pressure?
He flipped over a glass tube filled with mercury into a tub filled with mercury and noticed how the mercury level change from day to day. This was called a Mercury Barometer
What did standard pressure used to be defined as?
760 Torr or 760mm Hg in honor Torricelli
What is 760 mm Hg equal to?
1 atm or 101.325 kPa
What happens to gases as pressure increases?
Their volume decreses