Pressure, Temperature and RMS Speed

Now consider our first kinetic theory problem. Imagine a gas, consisting of n moles being confined to a cubical box of volume V. ''What is the connection between the pressure p exerted by the gas on the walls and the speeds of the molecules?" Pressure is defined as Force divided by Area or  where . Using Newtonian Mechanics, shows that

where n is the number of moles, M is the mass of 1 mole of the gas (so that nM is the total mass of the gas), v_RMS is the average speed of the molecules and V is the volume of the gas. The above equation is derived purely from applying Newtonian mechanics to the individual molecules.  Now by comparing to the ideal gas law pV = nRT or we must have or

which shows that the temperature T is related to the speed of molecules!

As shown the speed of molecules at room temperature is very large; about 500 m/sec for air (about 1000 mph).

مواضيع ذات صلة

قاعدة الطور

الغليان والتجمد

الحالات الوسيطة للمادة

الحالة الصلبة

الحالة السائلة

الحالة الغازية

منظور إحصائي

التفاعلات الجزيئية

المادة من الخارج

الرابطة التساهمية

الرابطة الأيونية

Chemical kinetics