Module 11 chemistry the Gas phase

What is pressure?

The force per unit area exerted on an object.

P=F/A

What os the units for newtons/m² named?

Pascal (abbreviated Pa)

how do gasses exert pressure?

Because the molecules are constantly moving quickly, they collide with the things around it, this is called gas pressure.

What is the atmospheric pressure usually?

101.3 kiloPaskals (kPa) or 1.000 atmosphere (atm)

What are two alternatives to units of measurement besides atm and kPa?

Millimeters of mercury (mm Hg) and torr

1.00 atm is equal to what kPa, mm Hg, and torr?

101.3 kPa, 760.0 mm Hg, 760.0 torr

Boyle said as long as the temperature of gas stayed the same…

The product of a gases volume and pressure is always the same

When the volume of Gas is increased, what will the pressure do?

Decrease

If the volume of gas is decreased, the pressure will do what?

Increase

What did Jacques Charles discover?

When gas temperature is increased (under constant preassure), the volume increases as well

Charles law:

At constant pressure , the temperature and volume of a gas are proportional

V/T= constant

What is the lowest C° we can get to?

-273.15°C

What is kelvin considered?

Absolute temperature scale

Can we ever reach 0.00 kelvin?

No

What is extrapolation?

Following an established trend in the data even though there is no data available for that region

The product of a gas’s pressure and volume decided by the gas’s temperature, remains the same despite the conditions under which the gas is stored.

PV/T=constant

When using any equation in this module you must always know what?

Kelvin temperature scale

How to get from C° to K ?

Add 273.15

What is ideal gas?

In order for the laws we’ve learned to work, they must behave in an ideal manner.

What is the first manner of ideal gasses?

1: the molecules (or atoms) that make up the gas are very small compared to the total volume available to the gas.

What is the second manner of idea gasses ?

2: the molecules (or atoms) that make up the gas must be so far apart from one another that there is no attraction or repulsion between them

What is the third manner of an idea gas?

2: the collisions that occur between thee gas molecules (or atoms) must be elastic. In other words, when the molecules (or atoms) collide, no energy can be lost in the collision. Also, no energy can be lost when the molecules (or atoms) of gas collide with the walls of the container.

Gasses tend to behave ideally at what?

High temperatures and low pressures

What is standard temperature and pressure? (STP)

A temperature of 263 K and a pressure of 1.00 atm

A temperature that is close to (or larger than) 273 K and a pressure that is near (or lower than) 1.00 atm will do what?

Behave in an ideal fashion. Under those conditions we can use ALL of the equations in this module.

Dalton’s law of partial pressures

When two or more idea gasses are mixed together the total pressure of the mixture is equal to the sum of the pressures of each individual gas

What is vapor pressure?

The pressure exerted by the vapor that sits on top of any liquid

The vapor pressure ______ with increasing temperature

Increases

What is boiling point?

The temperature at which the vapor pressure of a liquid is equal to normal atmospheric pressure

how to express Charles law?

If the ratio of volume and temperature must remain constant, then when temperature is increased, volume must increase as well

P1=X1P1

Partial pressure of any gas in a mixture depends on the mole fraction and total pressure of the gas mixture