Question

Assuming that seawater is an aqueous solution of NaCl, what is its molarity? The density of seawater is 1.025 g/mL at 20 ∘C, and the NaCl concentration is 3.50 mass %.

Answer 1

Answer:

0.6139M

Explanation:

A 3.50% by mass of NaCl means there are 3,50g of NaCl in 100g of solution. To find molarity we need to convert the mass of NaCl to moles and mass of solution to liters as follows:

Moles NaCl -molar mass: 58.44g/mol-:

3.50g NaCl * (1mol / 58.44g) = 0.05989 moles of NaCl

Liters solution:

100g solution * (1mL / 1.025g) * (1L / 1000mL) = 0.09756L of solution

Molarity -Ratio of moles and liters-:

0.05989 moles of NaCl / 0.09756L of solution =

0.6139M