can't figure these two out
1.  In the following equation-
2H2 + O2--> 2H2O

How many grams of O2 react with 2 grams of H2?


2.  In the following equation-
3H2 + N2--> 2NH3

How many moles of H2 react with 1 mole of N2?

Ok.1st you must now that coeficiants with the molecules/atoms etc Chemical reactions in General tells about the moles in which the react.

So when you say,

2H₂ + O₂----->2H₂O

It means that 2 Moles of Hydrogen gas react with one Mole of Oxygen to give two moles of Water.

After this step you can convert the Moles in the Gram Atomic Mass form.This Means 4gm of Hydrogen reacts with 32gm of oxygen to give 36gm of water.

Now since 32gm react with 4gm you can calculate how much of what will react with other.Its simple unitary method.

About that 2nd question it is more simple you can solve it without even converting the constituents to their Gram Atomic Mass.


And Read your Textbooks it will give you every Idea to Solve the problems.And if there is any Doubt you can put it on the Forum but 1st show that you have atleast attempted the problem.