What Mass of Na₂SO₄ Must Be Dissolved in 100 $\circ$ C? the Freezing Point Depression Constant,K_fp,of Water Is -1

Multiple Choice

What mass of Na₂SO₄ must be dissolved in 100.0 grams of water to lower the freezing point by 2.50 ^$\circ$ C? The freezing point depression constant,K_fp,of water is -1.86 ^$\circ$ C/m.Assume the van't Hoff factor for Na₂SO₄ is 2.85.

A) 3.77 g
B) 6.36 g
C) 6.70 g
D) 11.3 g
E) 19.1 g