Question

How many grams of NH3 are needed to provide the same number of molecules as in 0.85 grams of SF6?

Answer 1

This makes no sense to me whatsoever.

Answer 2

above it says the molecular weights are
NH3- 17g/mol and SF6-146 g/mol

Answer 3

The question asks "what is the mass of NH3 when \(n_{NH_3}=n_{SF_6}\)?".

SO, find the moles are equivalent 0.85 grams of SF6.

Use those moles to find the mass of NH3.

Answer 4

Well 1 mole of SF6 is 146.048 grams (i added hte atomic masses of each element)

so then the number of moles in 0.85 grams would be 0.00582000438 moles

i just did a simple proportion:\[\frac{ 1 mole }{ 146.048 g }*0.85g\]

so we would need 0.00582000438 moles of NH3 to have the same number of molecules

one mole of NH3 is 17.030519999989988 grams (i added each atoms mass)
so 0.00582000438 moles of NH3 would be:
\[\frac{ 17.030519999989988g }{ mole }*0.00582000438 moles\]

that equals 0.09911770099 grams
so 0.09911770099 grams is the answer if you round that you get about 0.1 grams