Question

seleccione la respuesta correcta. a520 gramosuna muestra de agua de mar contiene 0.317 moles de nacl.¿cuál es la composición porcentual de nacl en el agua? a. 1.1% b. 2.8% do. 3.6% d. 6.1%

Explanation:

Step1: Calculate mass of NaCl

The molar mass of NaCl is $M_{NaCl}=22.99 + 35.45=58.44$ g/mol. Given $n = 0.317$ moles, using $m=n\times M$, we have $m = 0.317\times58.44= 18.52548$ g.

Step2: Calculate percentage composition

The mass of the seawater sample is $m_{total}=520$ g. The percentage composition of NaCl is $\frac{m}{m_{total}}\times100\%=\frac{18.52548}{520}\times 100\%\approx 3.6\%$.

Answer:

C. 3.6%