What is the molality of 85% phosphoric acid if the density of the solution is 1.7 g/ml?(check my answer)?

Question

85% phosphoric acid could translate to 85g of H3PO4/ 100mL of solution. Molar Mass of H3PO4= 98g/mol

So,

(85 g H3PO4/ 100 mL solution) * (mol/98g H3PO4) * (mL/ 1.7 g) * (1000g/ 1kg)= 5 m

Is 5 m the answer? I didn't use a calculator, so the real answer might be off a little bit.

Answer 1

1700 g/L x 85 / 100 = 1445 g/L of H2PO4 in the solution

1445 g/L / 98 g/mol =14.7 M

mass water = 1700 - 1445 =255 g => 0.255 Kg

molality = 14.7 mol / 0.255 Kg =57.6