When a 1.00 L sample of water from the surface of the Dead Sea (which is more than 400 meters below sea level and much saltier than ordinary seawater) is evaporated, 196 grams of MgCl2 are recovered. What is the molarity of MgCl2 in the original sample?

2.06 M

Explanation:

number of moles of MgCl₂ = mass given in gram / molar mass

molar mass of MgCl₂ = 95.211 g/mol

number of moles of MgCl₂ = 196 g / 95.211 g/mol = 2.06 mol

Molarity of MgCl₂ in the original sample = number of moles / volume in Liters = 2.06 mol / 1 L = 2.06 M