The answer would be b, or 2
(sample g/1) X (1 mole/40.078(MW of Ca)) = moles of sample (moles of sample)(6.022 x 10^23( no of atoms)/ 1 mole) = # of atoms in a 120 g sample of calcium Avogadro's number=6.022x 10^23 atoms in 1 mole
<u>Answer:</u>
<em>0.264 g of
can be formed from 288 mg of
</em>
<u>Explanation:</u>
The balanced chemical equation is

The conversions are
Mass in mg
is converted to mass in g
Mass in g
is converted to moles
by dividing with molar mass
Moles
is converted to moles
by using the mole ratio of
is 9 : 6
Moles
is converted to mass
by multiplying with molar mass 
mass in mg
> mass in g
>moles
> moles
> mass 

=0.264g (Answer)
Answer: The molecular mass of this compound is 131 g/mol
Explanation:
Depression in freezing point:
where,
= depression in freezing point =
= freezing point constant = 
m = molality
i = Van't Hoff factor = 1 (for non-electrolyte)
= mass of solute = 0.49 g
= mass of solvent (cyclohexane) = 20.00 g
= molar mass of solute = ?
Now put all the given values in the above formula, we get:
Therefore, the molar mass of solute is 131 g/mol