More help needed! What does (w/w) mean and how do I solve this problem?

Question

A 85% (w/w) solution of H3PO4 (98.00 g/mol) has a density of 1.71 g/mL. What is the molarity of this solution?

Answer 1

w/w means weight by weight.

1 l of the soln weighs = 1.71x1000 g = 1710 g

Mass of H3PO4 present = 0.85 x 1710 g = 1453.5

Number of moles of H3PO4 = 1453.5/98 = 14.83

Thus molarity is 14.83

Answer 2

w/w
an abbreviation for "by weight," used in chemistry and pharmacology to describe the concentration of a substance in a mixture or solution. Properly speaking, 85% w/w means that the mass of the substance is85% of the total mass of the solution or mixture. The metric symbol g/g has the same meaning as w/w.

Answer 3

d=m/V
1,71= m/1000ml ( if we have 1 lt solution)

m=1710g (weight of the solution)

100 g solution contains 85 g H3PO4
1710 g solution contains x g H3PO4
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x=1453 g H3PO4

n=m/Ma

n=1453/98
n=14,82 mol

M=n/V
M=14,82/1

M= 14,82 mol/lt