1 / 35

# Unit G - PowerPoint PPT Presentation

Unit G . The Gas Laws. Properties of Gases. Gases form homogeneous mixtures Gases are compressible All gases have low densities air 0.0013 g/mL water 1.00 g/mL iron 7.9 g/mL Gases expand to fill their containers uniformly A gas exerts a pressure. Pressure.

Related searches for Unit G

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about 'Unit G' - terena

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### Unit G

The Gas Laws

• Gases form homogeneous mixtures

• Gases are compressible

• All gases have low densities

• air 0.0013 g/mL

• water 1.00 g/mL

• iron 7.9 g/mL

• Gases expand to fill their containers uniformly

• A gas exerts a pressure

• Defined as force per unit area

• 101.325 kPa

• = 760 mmHg

• =760 torr

• =1 atm

• =30 in Hg

• =14.7 psi

• Boyles Law pressure (Denali) is 606 mm Hg on a certain day. What is the pressure in atmospheres?  -- volume 

• P1/V PV = k

• Charles Law temperature  -- volume 

• VT V/T = k' (T must be in K)

• Avogadros Law moles  -- volume 

• V  n V/n = k''

• Gay Lussac Law temperature  -- pressure 

• P  T P/T = k'''

Ideal Gas Law (Denali) is 606 mm Hg on a certain day. What is the pressure in atmospheres?

PV = nRT

• P = pressure (typical units are atm or torr or mm Hg)

• V = volume (typical units are L)

• n = number of moles

• T = temperature (must be in K)

• R = gas constant = 0.0821 L atm/mol K

• = 62.4 L torr/mol K

• A container of 452 mL of argon is heated from 22 atm) and is allowed to rise to a height of 6.4 km, where the pressure is about 0.40 atm. Assuming that the temperature remains constant, what is the final volume of the balloon?oC to 187oC at constant pressure. What is its final volume?

• Sulfur hexafluoride (SF temperature and pressure are 86) is a colorless, odorless, very unreactive gas. Calculate the pressure (in atm) exerted by 1.82 moles of the gas in a steel vessel of volume 5.43 L at 69.5oC.

• A sample of nitrogen gas kept at 32 temperature and pressure are 8oC in a 2.3 L container exerts a pressure of 4.7 atm. Calculate the number of moles of gas present.

• Helium-filled balloons are used to carry scientific instruments high into the atmosphere. Suppose that a balloon is launched when the temperature is 22.5oC and the barometric pressure is 754 mm Hg. If the balloon’s volume is 4.19 x 103 L, what will it be at a height of 20 miles, where the pressure is 70.0 mm Hg and the temperature is 33.0oC?

• 3.67 x 104 L

• Chlorine is widely used to purify municipal water supplies and to treat swimming pool waters. Chlorine is stored in stainless steel cylinders of 30.0 L capacity at a pressure of 160 lb/in2 at 26oC.

• To what temperature may the cylinder be raised if it is rated to a maximum pressure of 15.35 atm? 14.7 psi = 1 atm

Standard Temperature and Pressure (STP) and to treat swimming pool waters. Chlorine is stored in stainless steel cylinders of 30.0 L capacity at a pressure of 160 lb/in

• T = 0oC = 273K

• P = 1 atm = 760 torr

• What volume will 3.21 moles of Ne occupy at STP?

• 71.9 L

• Stoichiometry with Gases 1.45 g/L at 44

• In 1774, Joseph Priestly heated mercury(II) oxide by using a lens to focus the rays of the sun on a sample of the red powder. It decomposed into its elements, and thus oxygen was discovered:

• 2 HgO(s)  2 Hg(l) + O2(g)

• Calculate the volume of oxygen, adjusted to STP, that is produced by decomposing 71.8 g HgO.

• Dolomite, the white rock used in gardens, is a one to one combination of calcium and magnesium carbonate. Another use is the manufacture of refractory brick for lining very-high-temperature furnaces. It is processed through a rotary kiln in which carbon dioxide is driven off:

• CaCO3MgCO3(s)CaO(s) + MgO(s) + 2CO2(g)

• For each kilogram of dolomite processed, how many liters of carbon dioxide escape to the atmosphere at 264oC and 1.09 atm?

• 437 L

• Sulfur burns to SO combination of calcium and magnesium carbonate. Another use is the manufacture of refractory brick for lining very-high-temperature furnaces. It is processed through a rotary kiln in which carbon dioxide is driven off:2 with a beautiful deep purple-blue flame, but with a foul, suffocating odor:

• 2 S(s) + O2(g)  2 SO2(g)

• How many liters of O2 are needed to form 35.2 L SO2, both gases being measured at 741 torr and 26oC?

• 17.6 L

• What if only the SO2 is at those conditions, but the O2 is at 17oC and 847 torr?

• 14.9L

• Gaseous chlorine dioxide, ClO combination of calcium and magnesium carbonate. Another use is the manufacture of refractory brick for lining very-high-temperature furnaces. It is processed through a rotary kiln in which carbon dioxide is driven off:2, is used to bleach flour and also in water treatment. It is produced by the reaction of chlorine with sodium chlorite:

• Cl2(g) + 2 NaClO2(s) 2 ClO2(g) + 2 NaCl(s)

• How many liters of ClO2, measured at 0.961 atm and 31oC, will be produced by 283 L of Cl2 at 2.91 atm and 21oC?

• 1770 L

Daltons Law of Partial Pressures combination of calcium and magnesium carbonate. Another use is the manufacture of refractory brick for lining very-high-temperature furnaces. It is processed through a rotary kiln in which carbon dioxide is driven off:

• Ptotal = P1 + P2 + P3 + ......

• the total pressure is equal to the sum of the pressures of the individual gases.

• The atmosphere of Venus contains the following gases. combination of calcium and magnesium carbonate. Another use is the manufacture of refractory brick for lining very-high-temperature furnaces. It is processed through a rotary kiln in which carbon dioxide is driven off:

• CO2 392 torr,

• N2 834 torr

• Ar 302 torr

• What is the atmospheric pressure on Venus?

Kinetic Molecular Theory combination of calcium and magnesium carbonate. Another use is the manufacture of refractory brick for lining very-high-temperature furnaces. It is processed through a rotary kiln in which carbon dioxide is driven off:

• Gases consist of molecular particles moving in straight lines at any given instant.

• Gas molecules are widely spaced, the actual volume of molecules is negligible compared to the space they occupy.

• Gas molecules demonstrate rapid motion, move in straight lines and travel in random directions. When they collide with each other they do so with no net loss of energy.

• Gas molecules behave independently -- attractive/repulsive forces between them are negligible.

• The average kinetic energy of the gas particles is proportional to the temperature.