Sio2 + 4hf = sif4 + 2h2o, what mass of hf is necessary to produce 12.91g of the sif4?

mass HF = 9.928 g

Explanation:

∴ Mw SiO4 = 104.0791 g/mol

∴ Mw HF = 20.01 g/mol

⇒ mol HF = 12.91 gSiF4 * (mol SiF4 / 104.0791 g) * (4 mol HF / mol SIF4) = 0.496 mol

⇒ mass HF = 0.496 mol HF * ( 20.01 g HF / mol HF ) = 9.928 g HF

the cold front replaces the warmer air at the ground level changing the wind to be breezy and denser.there is also an immediate drop in the temperature.