Answer:
B or 0.1538
Step-by-step explanation:
Remark
For every mol of NaN3 that decomposes, 3 mols of N2 are produced.
10000 mg = 10 grams
NaN3 = 23 + 3*14
NaN3 = 23 + 42
NaN3 = 65
So set up the following proportion
10 grams / 65 = x /1 Cross multiply
10 * 1 = 65 x Divide by 65
x = 10 / 65
x = 0.1538 moles which is B I think