Question

mass of 2 * 10^21 number of atoms of an element is 0.4g. what is the mass of 0.5 mole of the element?​

Answer 1

The mass of 0.5 moles of the element : 60.241 g

Further explanation

Given

mass of 2 x 10²¹ number of atoms of an element is 0.4 g

Required

the mass of 0.5 mole

Solution

Find relative atomic mass of the element(Ar)

mol of 2 x 10²¹ atoms :

`\tt n=(N)/(No)=(2.10^(21))/(6.02.10^(23))=3.32.10^(-3)`

`\tt Ar=(mass)/(mol)=(0.4)/(3.32.10^(-3))=120.482`

the mass of 0.5 moles :

`\tt mass=mol* Ar\\\\mass=0.5* 120.482=60.241~g`