What is the meaning of a h value of -400 kj in a reaction

Balance this equation: n2 + h2 > nh3, write the following molar ratios: n2 / n2 / nh3 h2 /

The table describes how some substances were formed substance 19 description formed by boiling pure water formed by combining three hydrogen atoms to every nitrogen atom formed by adding 5 g of sugar to 1 l of water formed by compressing carbon under high pressure based on the given descriptions, which substance is most likely a mixture?

Identify the missing numbers below to show the result of multiplying the numbers (1.6 × 10-19)(5.0 × 106) = c × 10d