Final answer:
The molar solubility of substance X is calculated by dividing the given solubility in grams per milliliter by the molar mass in grams per mole and converting to moles per liter, resulting in 3.74 × 10-12 mol L-1.
Step-by-step explanation:
To find the molar solubility of substance X, we must first convert the solubility in grams per milliliter to moles per liter (mol L-1). The solubility is given as 7.0 × 10-13 g mL-1, and the molar mass is 187 g mol-1. By dividing the solubility by the molar mass, we can find the molar solubility:
Solubility (mol L-1) = Solubility (g mL-1) / Molar mass (g mol-1)
Molar Solubility = (7.0 × 10-13 g mL-1) / (187 g mol-1)
To find the solubility in mol L-1, we multiply the solubility in g mL-1 by 1000 mL per L to convert to g L-1 and then divide by the molar mass:
Molar Solubility = (7.0 × 10-13 g mL-1 × 1000 mL L-1 / 187 g mol-1)
Molar Solubility = (7.0 × 10-10 g L-1 / 187 g mol-1)
Molar Solubility = 3.74 × 10-12 mol L-1