Question

A 520-gram sample of seawater contains 0.317 moles of NaCl. What is the percent composition of NaCl in the water?

Answer 1

The answer is in the photo.

Answer 2

3.56 %

Step-by-step explanation:

Percent composition of NaCl =
`(mass of NaCl)/(mass of sea water  )` x 100

Mass of sea water = 520 g

Moles of NaCl = 0.317 mol

Molar mass of NaCl = 58.44 g/mol

Mass of NaCl = moles of NaCl x Molar mass of NaCl

= 0.317 mol x 58.44 g/mol = 18.52 g

Percent composition of NaCl =
`(18.52 g)/(520 g)` x 100 = 3.56 %