Question

calculate the number of particles present in 0.25 moles of water molecule

Answer 1

Number of atoms in 1 mole of hydrogen gas = 2 x 6.022 x 1023

Number of atoms in 0.25 mole of hydrogen gas = 0.25 x 2 x 6.022 x 1023

                                                                             = 3.011 x 1023 atoms.

Answer 2

1 mole = 6.022*10^23 particles
0.25 moles = 0.25*6.022*10^23 particles
= 1.5055*10^23 particles

Hope the answer is correct...............