Physics Grade 10 Gas laws Isoprocesses Presentation (1)

Isoprocesses

Learning objectives

To investigate pressure and gas volume relationship at constant temperature (Boyle-Marriot law)

Law of Boyle-Mariotte (constant temperature)
Robert Boyle (1627–1691), Anglo-Irish philosopher, chemist and physicist
Edme Mariotte (1620–1684), French physicist and priest

For a fixed mass m of an ideal gas at constant temperature T, volume V and pressure p are inversely proportional

In a closed container, at constant temperature and constant amount of gas, individual molecules are constantly hitting and bouncing off the container walls.
Each time a gas molecule bounces, it imparts a force on the wall.
In a flexible container such as a balloon, the force of the molecules hitting the inside of the balloon hold the balloon inflated.
The force of each impact is small, but the sheer number of collisions create enough force to keep the balloon open.

Pressure in a closed container changes if
temperature changes
number of molecules increases or decreases
volume changes
Boyle’s Law deals with number 3; the relationship between volume and pressure when the other two remain constant.
According to Boyle’s Law, the amount a gas will compress is proportional to the pressure applied. Its mathematical expression is:
P1V1=P2V2 or PV = constant

1. Select all the options that apply to the graph and are physically reasonable for an ideal gas.
A. p as a function of T (n and V constant).
B. p as a function of V (n and T constant).
C. V as a function of n (p and T constant).
D. n as a function of T (p and V constant).
E. V as a function of p (n and T constant).

B; E

recall and understand that the ideal gas law can be simplified, if two variables are keep constant;

recall and solve problems using the equation of state for an ideal gas expressed as рV = nRТ when the amount of mass (number of moles) and temperature are constant;

describe the patterns due to changes in volume due to pressure with constant temperature (Law of Boyle-Marriote);

Learning Objectives - You should be able to: