Which event represents a chemical change? A. breaking glass B. chopping wood C. crushing a can D. milk turning sour

D

Explanation:

hi! a chemical change changes the composition of the material. in A, even though the glass is broken, it is still glass. for B, even though the wood is chopped, it is still wood. for C, even though the can is crushed, it is still a can. D is a chemical change because the milk's taste changes, meaning its chemical composition changed and a reaction occurred. it is no longer the original milk.

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