its chemistry :I

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

If we assume it is actually tin (III) fluoride, then you have....

1.24 g x 1 mol/176 g = 0.007 moles SnF3

moles F2 = 0.007 mol SnF3 x 3 mol F2/2 mol SnF3 = 0.0105 moles F2

@ STP 1 mol = 22.4 L, thus...

0.0105 moles x 22.4 L/mol = 0.235 L (3 sig. figs.)

Answer 2

Hi Bob

To do this calculation, you need to work through the process in terms of moles.

1. Convert 1.24 grams to of Tin Fluoride to moles ====> 0.007 moles
2. From the equation, 2 moles of SnFl3 create 3 moles of Fl2,
3. So, we would expect .007 moles of SnFl3 to create 0.0135 moles of Fl2
4. We also know that one mole of gas at STP occupies 22.4 liters
5. So, .0135 moles of Fl2 will occupy 0.302 liters, or 302 ml