Answer:
2NH3 + 2Na —> 2NaNH2 + H2
Step-by-step explanation:
NH3 + Na —> NaNH2 + H2
The above can be balance by doing the following:
There are a total of 4 hydrogen atoms on the right and 3 atoms on the left. This can be balance by putting 2 in front of NH3 and 2 in front of NaNH2 as shown below:
2NH3 + Na —> 2NaNH2 + H2
There are 2 atoms of Na on the right and 1 atom on the left. It can be balance by putting 2 in front of Na as shown below
2NH3 + 2Na —> 2NaNH2 + H2
Now we can see that the equation is balanced as we have equal numbers of atoms of the different elements on both sides of the equation.