Help with chemistry problem

If 3.98 liters of ammonia react with an excess
of oxygen at 500 degrees Celsius and 5 atm pressure,
4NH3(g) + 5O2(g) --> 4NO(g) + 6H2O(g)
what volume of steam will be produced at the
same temperature and pressure?


plz explain how you came up with the answer.

Observe that the Reactants and Products are gases, which enable us to use the Gay - Lusaac's law (combining law of gases)
4NH3(g) + 5O2(g) --> 4NO(g) + 6H2O(g)

Moles : Volume
4(NH3) : 3.98
6(H2O) : x

Now solve for x

4x = 6 * 3.98
x = 23.88/4
x = 5.7 liters

Therefore 5.7 liters of steam is produced.

My daughter had it right. Prateek's alternative method also works, but he made a mistake in his final calculation 23.88/4=5.97 NOT 5.7.
Had the products given a gas and a liquid then one would need to use molar mass and relative atomic mass too.

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5.97 liters

Go molar!
4 mols of ammonia make 6 mols of steam (H2O).
3.98 liters is 0.147 mols of ammonia using the molar volume of all gases.
So 0.147 / 4 and * 6 is 0.221 mols of steam.
Again using molar volume 0.221 mols is 5.97 liters.