# Physics

posted by
**maysam**
.

An ideal gas at 18.0 °C and a pressure of 2.83 x 105 Pa occupies a volume of 2.63 m3. (a) How many moles of gas are present? (b) If the volume is raised to 5.09 m3 and the temperature raised to 31.6 °C, what will be the pressure of the gas?

If N is the number of molecules then:

PV = NkT ---->

N = PV/(k T)

P = of 2.83 x 10^5 Pa

T = 291.15 K

V = 2.63 m^3

k = 1.38065*10^(-23)J K^(-1)

Calculate N and divide by 1 mole.

1 mole times the mass of one atomic mass unit is 1 gram.

1 atomic mass unit is 1.66054*10^(-27) kg ---->

1 mole is 6.02214*10^(23)

Remember: a mole is just a number just like a billion is a number!