Question

1.24g of Tin (III) fluoride is in a package of toothpaste decompose to Tin and Fluorine gas.

By this reaction: 2SnF3 (s) -> 2Sn (s) + 3F2 (g)

What volume of Fluorine gas will be produced at STP?

Answer 1

1.24g of Tin (III) fluoride in moles = $\frac{1.24}{156.69}=0.008$

we can see that ratio of stochiometric coefficients of SnF₃ to F₂ is 2:3

hence moles of fluorine gas formed will be 1.5 times of SnF₃

moles of fluorine gas =1.5$\times$ 0.008=$0.012$

1 moles = 22.4 lires at STP

hence 0.012 mole is equal to 0.2688 litres