Answer:
Molar mass = 151.9 g/mol
Explanation:
The molar mass of a compound is obtained by adding u the individual atomic masses in the compound. The unit is g/mol.
In FeSO4, we have one Fe, one S and 4 O.
The atomic masses are given as follows;
Fe = 55.845 u
S = 32.065 u
O = 15.999 u
Molar mass = ( 1 * Fe) + (1 * S) + (4 * O)
Molar mass = (1 * 55.854 ) + ( 1 * 32.065) + (4 * 15.999)
Molar mass = 151.915 g/mol
In four significant figures;
Molar mass = 151.9 g/mol
Answer:
Density of the He atom = 12.69 g/cm³
Explanation:
From the information given:
Since 1 mole of an atom = 6.022x 10²³ atoms)
1 atom of He = 

The volume can be determined as folows:
since the diameter of the He atom is approximately 0.10 nm
the radius of the He =
= 0.05 nm
Converting it into cm, we have:


Assuming that it is a sphere, the volume of a sphere is
= 
= 
= 
Finally, the density can be calcuated by using the formula :


D = 12.69 g/cm³
Density of the He atom = 12.69 g/cm³