Question

how many atoms are present in 36g of NH^4 ?​

Answer 1

Answer:

To start with there are 2 hydrogen atoms in a molecule of H2O.

In 1 mole of H2O, there are Avogadro number of molecules of H2O.

                                              .i.e, 6 x 10^23 molecules of H2O

As there are 2 hydrogens in a molecule of water, 

1 mole of H2O contains "2 x (6 x 10^23)" atoms of hydrogen.

36 grams is 2 moles of H2O.

So, 2 moles of water (36 grams) contain

 "2 x 2 x 6 x 10^23 = 2.4 x 10^24 atoms of hydrogen.