Question

Review Questions for Lab 4 (5 pr.) 1. How is gas unique? State the properties of a gas. 2 Write the equation for Boyle's Law. Explain in your own words the effect of pressure on the volume of a gas 3. What happens to a 8 L volume of gas as you move from a pressure of 3 atm to 4atm? Use the correct gas law to determine the new volume.

Answer 1

1)Gas is a state of matter that has no fixed shape and no fixed volume.Gases have lower density than other states of matter, such as solids and liquids.

• Gases have unique properties because the distance between the particles is so great

Gases behave like liquid because they can "flow "but have their own unique properties

properties of gases

1)Low density: Gases contain scattered molecules that are dispersed in a given volume therefore they are less denser than solid or liquid ,because of low density they flow like liquid .This low density allow gas particles to move rapidly and randomly.

2)Compressibility and Expandability: The low density of gases make it compressible therefore the molecules are positioned apart from one another .If a gas is compressible then it is expandable

3)Diffusivity: There are large amount of space between gas molecules ,two or more gases can be mix easily with one another to form a homogeneous mixture this is called diffusion

4)Indefinite Shape or Volume: Gases does not have definite shape and volume .They have shape and volume according to the container holding the gas

5)Pressure: Gas molecules are in constant motion ,they exert force per unit area ,or pressure on the interior surface of container .Pressure differ according to container which holds the gas.

Hence the gases have unique properties like low density ,diffusivity ,indifinite shape or volume , compressibility and expandabillity and pressure .

2) Equation of Boyle's law is

dP​/P=−dV​/V

According to Boyle's law, at a constant temperature, the volume of a given mass of a gas is inversely proportional to its pressure.

V∝1​/P

Or
PV=k Pressure multiplied by volume equals some constant k

where P is the pressure of the gas, V is the volume of the gas, and k is a constant

Law can be usefully expressed as:

(For comparing the same substance under two different sets of conditions)

$P_{1}V_{1}=P_{2}V_{2}.$ ​​​​​​​

where P1 and V1 are the initial pressure and volume values, and P2 and V2 are the values of the pressure and volume of the gas after change (final pressure and volume ).

This equation shows as volume increases, the pressure of the gas decreases in proportion. Similarly, as volume decreases, the pressure of the gas increases.

Hence according to Boyle's law :

For a fixed mass of an ideal gas kept at a fixed temperature, pressureand volume are inversely proportional.If volume increases, then pressure decreases and vice versa, when the temperature is held constant.

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