#### Answer

5.25 grams

#### Work Step by Step

From the coefficients in the equation, 2 moles of NaF are formed for 8 moles of HF reacted. If we have 0.5 moles HF then 0.5/8*2 = 0.125 moles of NaF are produced. Then we need the molar mass of NaF
Na is 22.99
F is 18.997
22.99 + 18.997 = 42 g/mol
If we have 0.125 mole then
0.125 mole * (42g/1mole) = 5.25 grams