The Gaseous State

Question 1

States of Matter

Answer 1

• Solid: Have definite volume and shapes
• Liquid: have definite volume but no definite shape; i.e., liquid will flow to assume any shape such as a container
• Gas: have neither definite volumes nor definite shapes,i.e., gases will expand by any amount to completely fill any container`

Question 2

Transformation between the different states of matter.

Answer 2

Solid and Liquid—> Gases: Sublimation and evaporation.

Gases—> Liquid or Solid: Condensation and decomposition

Question 3

Observable Properties of Gas

Answer 3

• Expansion and Compressibility
• Diffusion
• Low Densities
• Pressures
• Pressure as function of Temperature

Question 4

Thermometer

Answer 4

Temperature of gases, liquids and solids measured by …

Question 5

Absolute Temperature

Answer 5

K= Celcius + 273.15
Absolute Temperature (kelvin) scale is used to measure gas temperatures.

Question 6

Volume Measurements

Answer 6

Gas Volumes are usually measured by displacement of liquid.

Question 7

Eudiometer

Answer 7

The volume of a liquid displaced by a less dense gas is measured in a eudiometer.

Question 8

Absolute Pressure

Answer 8

Absolute Pressure is measured with a barometer– a tube enclosed at one end and entirely filled with liquid, then inverted so that some of the liquid flows out of the tube leaving the vacuum.

Question 9

Mercury

Answer 9

is the most dense pure liquid element, and can be relatively easily obtained and handled, mercury is commonly used as the standard liquid for pressure measurement.

Question 10

Torr (Unite of pressure measurement)

Answer 10

Used to represent the pressure equivalent to a height of 1mm of liquid mercury.

(1torr=1mmHg)

*Named in honor of the Italian Physicist Torricelli)

Question 11

Atmospheric Pressure

Answer 11

The Pressure exerted by the atmosphere pressing down on the earths surface…
*The Average atmospheric pressure at sea level is defined as being exactly equal to 760mmHg.

1atm = 760mmHg

Question 12

Relative Pressure

Answer 12

Measure of the differences in pressure between two systems which are connected together by a U-shaped tube partially filled with liquid.
Instrument used: Manometer

Question 13

Pressure

Answer 13

Pressure is the force exerted on an object divided by the area over which the force is exerted.

Question 14

Avogrado’s Hypothesis

Answer 14

Stated another way, the volume of a gas at a given temperature and pressure is directly proportional to the amount of gas in moles.