Question

calculate the number of moles for 52 gram of helium??

Answer 1

no of moles=mass in gm molar mass

= 52


4

=13 moles

Answer 2

Don't be confused in finding no. of moles .
Keep two formulas in mind to find no. of moles:
No. of moles=given mass / molar or molecular Mass
No.of moles =given no.of particles. / avagardo number.
(Molar and molecular mass are same only )
Answer to ur question:
(Molar mass of helium is 4)
No.of moles= given mass / molar or molecular mass
No.of moles=52/4
No.of moles =13