What is the molarity of the nitrate ions when 0.42 mol of barium nitrate, Ba(NO3)2, is.....

What is the molarity of the nitrate ions when 0.42 mol of barium nitrate, Ba(NO3)2, is dissolved in enough water to make 4.0 L of solution?

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Calculate the molarity of the hydroxide ions in a solution that has been prepared by dissolving 90.6 g of barium hydroxide (Ba(OH)2) in water and diluting the solution to a final volume of 2.00 L. ( Ba 137.3 g/mol., O 16.0 g/mol, and H 1.0 g/mol)



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Molarity = number of moles of solute/volume of solution in liters
= 0.42/4=0.105M
Each barium nitrate ionises to give 2 nitrate ions hence the molarity of nitrate ions is 2x 0.105 =0.21M
Number of moles of Ba(OH)2 = 90.6/167.3=0.542
Molarity = 0.542/2=0.271M
Each Ba(OH)2 ionises to give 2 OH- ions hence the molarity of hydroxide ions is 2x 0.271 = 0.542M