Respuesta :

Answer:

D. 18.7 grams

Explanation:

The coefficients are the key.

Create a proportion with them, and the molar mass, and then solve for x:

[tex] \frac{2}{3} = \frac{x}{28} \\ 3x = 2(28) \\ 3x = 56 \\ x = 18.666... = 18.7[/tex]