245 Mol/dm³ of HNO3 neutralizes 0.450 mol/dm² of 25 cm³ Na₂CO3.Calculate the Concentration of HNO3 in (a) mol/dm³ (b) g/dm³. HNO3(aq) + NO₂CO3(aq)→NaNO3(aq)+H₂OCO₂(g) (H=1, N = 14, 0=16, Na=23, C=12)
You need a volume of HNO3 used.
Plus I don't think you have a concentration of 245 M. Can't make HNO3 that strong.