Chemistry 1111: Test 2 - Ch. 5

Front 1

Gases

Back 1

> NOrmal Atmospheric conditions, defined as 25 deg Celsius, and 1 ATM pressure.

> Ionic compounds don't exist as gases at 25deg and 1atm.

> molecular compounds boil at much lower temp. than ionic compounds do.

> Stronger the intermolecular forces attractions, less likely a compound can exist as a gas at ordinary temp.

All gases have following characteristics
- Gases assume the volume and shape of their containers
- Gases are the most compressible of the states of matter
- Gases will mix evenly and completely when confined to the same container
- Gases have much lower densities than liquids and solids.

Front 2

5.2 Pressure of a Gas

SI Units of Pressure

Back 2

> Velocity: Change in distance w/ elapsed time
velocity = distance moved / elapsed time.

Si unit is m/s

> Acceleration is m/s2
acceleration = change in velocity / elapsed time.

> Force, unit in Newtons (N)
1N = 1kg m/s2

> Pressure = force / area

> SI Unit of Pressure, pascal (Pa). one newton per square meter.
1Pa = 1N/m2

Front 3

Atmospheric Pressure

Back 3

> atmosphere is much denser near surface of earth than at high altitudes. All matter is subject to Earths gravitational pull.

> Atmospheric pressure is the pressure exerted by Earth's atmosphere.

> Standard atmospheric pressure (1 atm) equals a pressure of 760 mmHg.
- mmHg represents the pressure exerted by a column of mercury 1mm high.
- unit in torr

1 torr = 1mmHg
1atm = 760 mmHg

1 atm = 101,325 Pa or 1.01325 x 10 (to the 5) Pa
1000 Pa = 1kPa (kilopascal)
1 atm = 1.01325 x 10 (to the 2) kPa

Front 4

5.3 Gas Laws

Back 4

> Pressure-Volume Relationship: Boyle's Law
- Pressure (P) is increased, vol occupied by the gas decreases.
- Conversely, pressure applied is decreased, Volume the gas occupies increases.
- Pressure/Vol inverse relationship.

> Inverse Relationship equation:
P proportional to 1/V
or P = k1 x 1/V
or PV = k1