Which of the following balanced chemical equations below best represents the following “word” equation: nitrogen gas reacts with hydrogen gas to produce ammonia.

n2 + 3h2 --> 2nh3

n + 2h2 --> 2nh

n2 + h2 --> nh3

n2 + 2h --> 2nh3

The answer to your question is the first option

Explanation:

According to the "word"equation:

Reactants =   Nitrogen gas = N₂(g)

                      Hydrogen gas = H₂(g)

Products  =    Ammonia =  NH₃

Reaction

                      N₂(g)  +   H₂(g)    ⇒   NH₃

Now, we have to balance it

                     Reactants            Elements           Products

                            2                          N                        1

                             2                         H                        3

This reaction is unbalanced.

Multiply NH₃ by 2 and H₂ by 3

                     N₂(g)  +  3 H₂(g)    ⇒  2 NH₃

Now, we have to balance it

                     Reactants            Elements           Products

                            2                          N                        2

                             6                         H                        6

Now the reaction is balanced

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.