Given data:
# atoms of Br in PBr3 = 3.68 * 10^25
Step-by-step explanation:
In PBr3,
1 mole of PBr3 contains 3 moles of Br
Now,
1 mole of Br contains Avogadro number i.e. 6.023 * 10^23 atoms of Br
Therefore, the # moles of Br corresponding to 3.68*10^25 atoms would be:
= 3.68 * 10^25 atoms * 1 mole Br/6.023*10^23 atoms = 61.099 moles of Br
Since,
3 moles of Br is present in 1 mole of PBr3
then, 61.099 moles of Br would correspond to:
61.099 moles Br * 1 mole PBr3/3 moles Br = 20.366 moles of PBr3
Ans: 20.4 moles of PBr3