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a cylinder of volume 2x10^-3 m^3 contains a gas at a pressure of 1.50MNm^-2 and at a temperature of 300K.

calculate number of moles. i think i'm ok with this bit:

n=(pV)/(RT)

=(1.5x10^6)x(2x10^-3) all divided by 8.31x300

gives 1.2033694...

calculate number of molecules.

number of molecules=number of moles x avocado's constant

=1.2033694 x 6.023x10^23

=7.224283x10^23

calculate the actual mass of the gas if the molar mass is 0.032kg

actual mass = number of moles x molecular mass

=32 x 1.2033694

=38.5078

now calculate the mass of one molecule of the gas.

erk! which equation do i use? i can't use the half-m-c-squared-bar ones cos i don't know speeds or anything!

help is appreciated.

i have yet another one! watch this space.

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# And for my next trick more ideal gases questions. the joy.

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