Question

A gas contained 33.3% of silicon and 67% of fluorine by mass.at 35 degrees and 0.210 liters of the compound exerted a pressure of 1.70 atm. If the mass of 0.210 liters of the compound was 2.39 grams calculate the molecular formula of the compound

Answer 1

Answer:

$Si= 33%     F= 67%</p><p></p><p>For 100 g of the compound, </p><p></p><p>moles of Si present = 33/28 = 1.1785 moles</p><p></p><p> </p><p></p><p>moles of F present= 67/19= 3.5263 moles</p><p></p><p> </p><p></p><p>dividing by the smallest number 1.1785 , we have,  Si= 1 mole , F= 3 moles</p><p></p><p>Hence the empirical formula is SiF3</p><p></p><p>$