Question

find the number of neutron in 0.45 gram water assuming that all the hydrogen atoms are H1 atoms and all the oxygen atoms are O 16 items

Answer 1

molecular weight of water is 18 gram/mole ,
so the mole of 0.45 gram water is 0.025.
so atoms in the 0.45 gram water is 0.025×6.022×10^23.
so number of neutrons in it is 8 × atoms in 045 gram of water.
so the answer is 1.2044×10^23 neutrons.

Answer 2

hey there !!

Hydrogen atom has 1 proton and oxygen atom has 8 protons thus,

in h2o molecule there will be 1×2+8 = 10 protons .

mol weight of h2o is 1×2 + 16 = 18gm

now ,

18gm of h2o = 1 mol.

than ,

in 0.45gm of h2o will contain = 0.45/18 = 0.025 mol. of water .

1 mole includes 6.023×10^23 molecules

Thus

in 0.45gm H2O

= 0.025gm.mol or 0.025 mole H2O

= 0.025× 2.023×10²³ H2O molecules

= 0.025× 2.023×10²³ × 10 prtons

hence no. of neutrons in 0.45gm of h2o is :-

0.025 × 2.023 × 10²³ × 10 neutrons

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