The balanced chemical equation for the reaction between ammonia (NH3) and nitric acid (HNO3) is:

NH3 + HNO3 → NH4NO3

From the equation, we can see that 1 mol of ammonia reacts with 1 mol of nitric acid to form 1 mol of ammonium nitrate.

Therefore, if we have 4 mols of ammonia, we will need 4 mols of nitric acid to react completely.

So, 4 mols of nitric acid can be obtained from 4 mols of ammonia.

The molar mass of nitric acid (HNO3) is:

H = 1.01 g/mol
N = 14.01 g/mol
O = 16.00 g/mol

Adding the atomic masses:
1.01 + 14.01 + (3 x 16.00) = 63.02 g/mol

Therefore, 4 mols of nitric acid will weigh:

4 mols x 63.02 g/mol = 252.08 grams

Thus, 252.08 grams of nitric acid can be obtained from 4 mols of ammonia.