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

Answer:

3.56 %

Explanation:

Percent composition of NaCl =  $\frac{mass of NaCl}{mass of sea water }$ 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 = $\frac{18.52 g}{520 g}$  x 100 = 3.56 %