Calculate the molarity
1. 420 gram of Na2co3 dissolved in enough water to form 1L

Solution:
Given, that the mass of Na₂CO₃  =420g
Volume of solution = 1 L
The molar mass of Na₂CO₃ = 106g/mol
Molarity = $\frac{mass of solute}{molar mass of solute \times Volume of solution \left(L\right)}$= $\frac{420}{106\times 1}= 3.96 M$