The question is incomplete, complete question is :
A chemist must dilute 73.9 mL of 400 mM aqueous sodium carbonate solution until the concentration falls to 125 mM . He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Be sure your answer has the correct number of significant digits.
Answer:
The final volume of the solution will be 0.236 L.
Explanation:
Concentration of sodium carbonate solution before dilution =
Volume of sodium carbonate solution before dilution = 
Concentration of sodium carbonate solution after dilution =
Volume of sodium carbonate solution after dilution = 
Dilution equation is given by:



1 mL = 0.001 L
236 mL = 0.236 L
The final volume of the solution will be 0.236 L.
I'd say it's single replacement/displacement
Magnesium is classified as a metal. Magnesium has two valence electrons
9.0 grams will produce 11 L of hydrogen