The question is incomplete, here is the complete question:
A chemist adds 180.0 mL of a 1.42 M sodium carbonate solution to a reaction flask. Calculate the mass in grams of sodium carbonate the chemist has added to the flask. Be sure your answer has the correct number of significant digits.
Answer: The mass of sodium carbonate that must be added are 40.9 grams
Step-by-step explanation:
To calculate the mass of solute, we use the equation used to calculate the molarity of solution:

Molar mass of sodium carbonate = 106 g/mol
Molarity of solution = 1.42 M
Volume of solution = 180.0 mL
Putting values in above equation, we get:

Hence, the mass of sodium carbonate that must be added are 40.9 grams