You dissolve 49.84 g of sodium chloride in 500 mL of water, what is the molarity of sodium cations in the solution as moles per litre?

First, we need to calculate the number of moles of sodium chloride (NaCl) in 49.84 g. The molar mass of NaCl is approximately 58.44 g/mol.

Number of moles = mass of substance / molar mass of substance Number of moles of NaCl = 49.84 g / 58.44 g/mol = 0.853 moles

In NaCl, the ratio of Na+ ions to Cl- ions is 1:1. Therefore, the number of moles of Na+ ions is also 0.853 moles.

Next, we need to convert the volume of the solution from milliliters to liters. 500 mL = 0.5 L.

Finally, we can calculate the molarity (M) of the solution, which is defined as the number of moles of solute per liter of solution.

Molarity = number of moles / volume in liters Molarity of Na+ ions = 0.853 moles / 0.5 L = 1.706 M

So, the molarity of sodium cations in the solution is 1.706 moles per liter.