The molarity of a solution is the number of moles of a substance divided by the volume in liters prepared.
, where n is number of moles and V is the volume in liters.
In order to calculate the mass of solute we need to convert the volume and molarity to moles

Now that we have moles we use the relative formula mass of NaCO₃, We have 1 Na atom, 1 C atom and 3 O atoms, thus


Answer:
Explanation:
The formula for sodium is Na. It does not form a molecule in some way.
1 mol Na = 6.02*10^23 atoms
3.91 mol = x Cross multiply
x = 3.91 * 6.02 * 10^23
x = 23.65 * 10^23
x = 2.365 * 10^24
Scientific notation is always expressed as a number 1 ≤ x < 10
The answer for this would be 69.6