What is % w/w of 18 m naoh? density 1.48 g/ml?

As,

w/w % = weight of Solute / Weight of Solution * 100 - - - (1)

Finding weight of Solute:

As,

1 mole of NaOH = 40 g

So,

18 moles = X g

Solving for X,

X = (18 mol * 40 g) : 1 mol

X = 720 g

Finding mass of Solution:

Multiply density of the solution by 100 mL

So,

= 1.48 g/mL * 1000 mL

= 1480 g

Putting values in eq. 1,

w/w % = 720 g / 1480 * 100

w/w % = 48.64 %