Question

What is the mass of SO3 with the volume 45 ml?

Answer 1

@kainui @parthkohli can you help me plz?

Answer 2

I'm assuming this is a gas?

If so, first off we will need to find the moles of SO3. I prefer to work in cm^3 for gaseous substances, however ml and cm^3 are the same anyways (1 cm^3 = 1ml)

So to find the moles of any gaseous substance, you will have to do:
volume of substance (in cm^3) / 24000cm^3 (volume that 1 mol of any gaseous atom has)

So: 45 / 24000 = 1.875 x 10^-3 mol (My calculator showed it in standard form, basically the number is 0.001875 mol) You can round this to 3 significant figures if needed.

Now we have the no. of moles, we can work out the mass (in grams) of SO3.
We do that by doing this equation:

mass = moles x molar mass
Molar mass of SO3 = 24.3 (sulfur) + (16 x 3) (3 oxygens) = 72.3 g mol^-1

So now plug in the values: (1.875 x 10^-3) x 72.3 = 0.136g (3 significant figures)

So your answer should be 0.136g of SO3 :)

Feel free to correct me, I'm not sure if you were talking about a gaseous substance or not, but if you were then this should help.