Answer:
The coefficient of the Ammonia gas is 2
Explanation:
N2 + H2 ==> NH3
Put a 2 in front of the NH3 to get the Ammonia balanced with the right number of nitrogens.
N2 + H2 ==> 2NH3
Now the problems is the hydrogens. There are 2 on the left and 2*3=6 on the right. The number of hydrogens is the number in the molecule * the balance or 3 * 2 = 6
But you have 2 in the hydrogen molecule. So you need 3 more molecules.
N2 + 3H2 ==> 2NH3