Determine the molar concentration of sodium oxide if 3.91g of solid was added to 525mL of solution.

I am not typing my entire work in but I calculated these values:
V=525 ml= 0.525L
N= 0.0603084866

Would it be 0.120 mol/L

2 answers

well I guess you are adding it to pure water

3.91g * (1000mL/L)/525 mL = 7.45 grams/liter

but we want mols per liter

Na2O is 62 g/mol because 2 * 23 + 16

7.45 g/L /62 g/mol = .12 mol/L
So my answer is right?