How many grams are in 0.02 moles of bel2

Molar mass of bei2 (262.8 g), you multiply its mass, by amount of moles they give you, which is (0.02 moles). 


262.8 g ) 
0.02 moles x = 5.256 g in (0.02 moles of bei2) 
1 mol bei2)

Most likely a is the answer - because  you generate   38 atp's but also consume an atp.   each atp gives approx. less than 4 kcal so probably a is the closest answer.