Question

Josh prepares a solution by mixing sodium nitrate and water. To calculate the molarity of the solution, Josh should calculate the moles of which substance, and why?
1 sodium nitrate, because it is the solvent
2 sodium nitrate, because it is the solute
3 water, because it is the solvent
4 water, because it is the solute

Answer 1

Sodium nitrate because it is the solute. If Josh knows how many moles of NaNO3 he dissolves and the volume of water (solvent) he dissolved it in, concentration = moles / volume

Answer 2

Answer: The correct answer is option 2.

Explanation:

$\text{moles of compound}=\frac{\text{Mass of the compound}}{\text{Molar mass of the compound}}$

$Molarity=\frac{\text{Mass of the solute}}{\text{Molar mass of the solute}\times \text{Volume of the solution in Liters}}}$

Josh prepares a solution by mixing sodium nitrate and water that is sodium nitrate is a compound which is dissolved in water(solvent) as solute.

Solution : Sodium Nitrate + water

$Molarity=\frac{\text{Mass of the}NaNO_3}{\text{Molar mass of the}NaNO_3\times \text{Volume of the solution in Liters}}}$

Josh should calculate the moles of sodium nitrate, because it is the solute.