How do I the molarity of 200 mL of solution in which 2.0 moles of sodium bromide is dissovled?
Just remember the definition.
molality = # mols/kg soln
My glasses need refurbishing. I misread your question. The MOLARITY (I thought it said molality) = # mols/L soln.
To calculate the molarity of a solution, you need to know the amount of solute (in moles) and the volume of the solution (in liters).
In this case, the given information is that 2.0 moles of sodium bromide (NaBr) is dissolved in 200 mL of solution.
First, you need to convert the volume from milliliters (mL) to liters (L). There are 1000 mL in one liter, so 200 mL is equal to 200/1000 = 0.2 L.
Next, divide the number of moles of solute by the volume of the solution in liters. In this case, divide 2.0 moles by 0.2 L:
Molarity (M) = moles of solute / volume of solution in liters
M = 2.0 mol / 0.2 L
M = 10 M
Therefore, the molarity of the solution is 10 M (moles per liter).