Determine the amount of heat (in kJ) given off when 1.26 × 104𝑔 of NO 2 are produced according to the equation: 2𝑁𝑂(𝑔) + 𝑂2(𝑔) → 2𝑁𝑂2(𝑔) ∆𝐻 = −114.6𝑘𝑗/𝑚𝑜𝑙

Answer 1

2𝑁𝑂(𝑔) + 𝑂2(𝑔) → 2𝑁𝑂2(𝑔) ∆𝐻 = −114.6𝑘𝑗/𝑚𝑜𝑙
How many moles do you have in1.26 × 104𝑔 (12,600 g) NO2?
So you get 114.6 kJ for 1 mol NO2 produced. You will get 2*114.6 kJ = 229.2 kJ for 2 mol NO2 produced. 2 mols NO2 = 2 mols x 46 g/mol = 92 grams; i.e., you will get 229.2 kJ for 92 g NO2 produced. How many kJ will you get for 12,600 g? That's
229.2 kJ x (12,600 g/92 g) = ? kJ.