A student notes that a Chunk of Wood is much lighter after it has breen burned. He concludes that burning a substnce destroyes some of that mass in that substance. Do you agree or Disagree with this statement explain why or why not.

calculate how many grams of ammonia can be produced from 4.21 grams of

n2 + 3h2 = 2nh3

my answer:

25.0g n2 x (1 mol/ 28.0gn2) x (2 mol nh3/ 1 mol n2) x (17.0g nh3/ 1 molnh3) = 30.36g n2

25.0g h2 x (1 mol h2/ 2.00g h2) x (2 mol nh3/ 3 mol h2) x (17.0g nh3/ 1 mol nh3) = 141.67g h2

lr = n2

b. is the answer hoped i        

it would be b. 6co2 + 6h2o --> c6h12o6 + 6o2

o conteúdo de calor de um sistema é igual à entalpia apenas para um sistema que é constante