Tin fluoride, SnF2, is used in some toothpastes. It is made by the reaction of tin with hydrogen fluoride according to the following equation: Sn(s) + 2HF(g) --> SnF2(s) +H2(g). If a toothpaste manufacturer reacts 30.00 of HF with enough tin, how many grams of SnF2 can they expect to get? Please show your work or how you got the answer, I really need it.

Mass of SnF2 : 117.53 g

Given

Reaction

Sn(s) + 2HF(g) --> SnF2(s) +H2(g).

30 g of HF

Required

mass of SnF2

Solution

mol HF (MW= 20 g/mol) :

= mass : MW

= 30 : 20

= 1.5

From the equation, mol ratio of HF : SnF2 = 2 : 1, so mol SnF2 :

=1/2 x mol HF

= 1/2 x 1.5

= 0.75

mass SnF2(MW=156.71 g/mol) :

=mol x MW

= 0.75 x 156.71

= 117.53 g

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e