Cherylyn L. answered 10/01/19
PhD in Chemistry with 10 years of Tutoring and Teaching Experience
According to the following reaction, how many grams of bromine trifluoride are needed to form 21.5 g fluorine gas? bromine trifluoride (g) bromine (g) + fluorine (g)
You must first write the formulas for the compounds (called the skeleton equation), then balance the equation.
Skeleton equation is BrF3 Br2 + F2 (bromine and fluorine are diatomic elements)
Balanced equation is 2 BrF3 Br2 + 3 F2
Asked / given ................? g ...................21.5 g
Molar masses..........136.9 g/mol ............38.0 g/mol
Begin with the quantity you are given in the problem, 21.5 g F2
Overall, the steps are:
1 convert mass F2 to mol F2 using the molar mass of F2;
2 convert mol F2 to mol BrF3 using the coefficients from the balanced equation (stoichiometry)
3 convert mol BrF3 to g BrF3 using the molar mass of BrF3
21.5 g F2 x 1 mol F2/38.0 g F2 = answer #1 (unit is mol F2)
answer #1 (mol F2 ) x 2 mol BrF3/3 mol F2 = answer #2 (unit is mol BrF3)
answer #2 (mol BrF3 ) x 136.9 g BrF3 /1 mol BrF3 = answer #3 (unit is g BrF3)