Answer to Question #161212 in General Chemistry for neyola rebello

Question

Calculate the amount of heat released (kJ) in the complete oxidation of 6.95 g of Al metal at standard condition. 

4 Al(s) + 3 O₂(g) → 2 Al₂O₃(s)      ΔH° = -3352 kJ

Answer 1

Atomic mass of Al is 27 g/mole

6.95g of aluminium =(6.95/27)=0.25moles of Al

According to given equation 4 moles Aluminium produce 3352kj heat during oxidation,

0.25 moles Al produce (3352*0.25/4)=209.5kj