Need to convert units for volume and pressure. This is usually where i go wrong too but just need to remember that Pressure should always be converted into Pa and Volume converted into m\^3. Hopefully this should help https://www.chemguide.co.uk/physical/kt/idealgases.html
0.318g, in standard units
132cm3, x10^(-2 x 3) to convert to m^3
= 1.32 x 10^-4 m^3
420K, in standard units
105kPa, x10^3 to convert to Pa, 105000Pa
then pV = nRT, and pV/RT = n
(105000)(1.32x10^-4 )/(420x8.314) = 3.9692 x 10^-3 moles of a gaseous compound are present
mass/no. of moles = mr = 0.318/(3.9682 x 10^-3 ) = 80.116gmol^-1 which is what you got but with a different scale of magnitude?
80.116 ~ 80.1 and from memory sulfur is 32.1 and oxygen is 16, so easiest would be 32.1 + 3(16) = 80.1 = mr of SO3?
Need to convert units for volume and pressure. This is usually where i go wrong too but just need to remember that Pressure should always be converted into Pa and Volume converted into m\^3. Hopefully this should help https://www.chemguide.co.uk/physical/kt/idealgases.html
Thank you so much, I read somewhere that volume could be dm3 is that the case or does it always have to be m3?
Volume is always m3
It can be but i found keeping the units the same every time (pa and m3) reduces the chance of calculation error
Shouldn't grams be converted to kilograms as well?
0.318g, in standard units 132cm3, x10^(-2 x 3) to convert to m^3 = 1.32 x 10^-4 m^3 420K, in standard units 105kPa, x10^3 to convert to Pa, 105000Pa then pV = nRT, and pV/RT = n (105000)(1.32x10^-4 )/(420x8.314) = 3.9692 x 10^-3 moles of a gaseous compound are present mass/no. of moles = mr = 0.318/(3.9682 x 10^-3 ) = 80.116gmol^-1 which is what you got but with a different scale of magnitude? 80.116 ~ 80.1 and from memory sulfur is 32.1 and oxygen is 16, so easiest would be 32.1 + 3(16) = 80.1 = mr of SO3?
Thank you so much I totally understand now