Question

Fluorine is so reactive that it forms compounds with materials inert to other treatments. When 0.622 g of platinum is heated in fluorine, 0.985 g of a dark red, volatile solid forms.

When 0.378 g of this red solid reacts with 0.161 g xenon gas, 0.539 g of an orange-yellow solid forms. What is the empirical formula of this product, the first to contain a noble gas?

Answer 1

Molar Mass of Platinum = 195.084g/mol

Mass of Platinum = 0.622g

No of mole of Platinum = 0.622g/195.084g = 0.003188g

Mass of dark red compound = 0.985g

Mass of Flourine reacted = 0.985g - 0.622g = 0.363g

Molar mass of Flourine = 18.998g

No of mole of Florine reacted = 0.363g / 18.998g = 0.019107

Ratio of flourine / platinum

Flourine / Platinum = 0.019107/0.003188= 5.993 = 6

So , the empirical formula of dark red compound is PtF₆ ( Platinum hexaflouride )

Molar mass of PtF₆ = 309.07g/mol

Mass of PtF₆ reacted = 0.378g

No of mole of PtF₆ reacted = 0.378g/309.07g =0.001223

Mass of Xe gas reacted = 0.161g

Molar mass of Xe = 131.296g/mol

No of mole of Xe gas reacted = 0.161g/131.296g = 0.001226

Ratio of PtF₆/Xe is 1:1

Therefore ,

the empirical formula is XePtF₆ ( Xenon hexaflouroplatinate )