Answer :
(a) The moles of is, 1.5 moles.
(b) The number of oxygen atoms are,
(c) The mass of oxygen is, 72 grams.
Explanation : Given,
Mass of = 150 g
Molar mass of = 100 g/mole
Molar mass of oxygen = 16 g/mole
(a) First we have to calculate the moles of .
The moles of is, 1.5 moles.
(b) Now we have to calculate the number of oxygen atoms.
In , there are 1 atom of chromium and 3 atoms of oxygen.
According to the mole concept,
1 mole of contains
number of oxygen atoms.
So, 1.5 mole of contains
number of oxygen atoms.
The number of oxygen atoms are,
(c) Now we have to calculate the mass of oxygen.
As, 1 mole of contains 3 moles of oxygen
So, 1.5 mole of contains
moles of oxygen
The mass of oxygen is, 72 grams.
