Do the following problems in your lab notebook. Be sure to specify the knowns & unknowns, the formulas used, show your work with labeled units and round you’re answers to the appropriate significant figures.
15-1 Molarity Problems: (M = moles/ liter )
1. What is the molar concentration of a 415 ml solution containing 0.745 moles of HCl? (A: 1.80 M HCl)
2. What is the molar concentration of an acetic acid (CH3COOH) solution containing 3.21 moles in 4.50 liters? (A: 0.713 M)
3. How many moles of KI are present in 125 ml of 0.500 M KI? (A: 0.0625 mol KI)
4. How many moles of ammonia (NH3) are present in .360 L of 2.13 M NH3 solution in water? (A: 0.767 mol NH3)
5. How many liters of water are required to prepare a solution of 7.25 M MgCl2 from 4.89 moles of MgCl2? (A: 0.674 L)
6. What is the molarity of a solution prepared by adding 58.5 g of NaCl to 230 ml of H2O? (A: 4.3 M NaCl)
7. What is the molarity of a KNO3 solution prepared by adding 151.5g of KNO3 to 300ml of H2O? (A: 5.00 M KNO3)
8. How many grams of NaOH are required to prepare 2.0 liters of 2.5 M NaOH solution in water? (A: 200g NaOH)
9. What is the molarity of a soltuion prepared by dissolving 5.68 g of NaOH in enough water to make 400. ml of solution? (A: 0.355M)
10. If a 2.34 g sample of dry ice, CO2, is dropped into a sealed 500 ml bottle of orange cool aid, and the CO2 gas released dissolves virtually completely in the cool-aid, what is the approximate concentration of CO2 in the now carbonated cool aid? (A: 0.1 M)
11. How many grams of HCl are required to prepare 250 ml of a 0.158M solution? (A: 1.5g)
12. Vinegar is a solution of acetic acid. What is the molarity of the solution produced when 125g of acetic acid (C2H4O2) is dissolved in sufficient water to prepare 1.50 L of solution? (A: 1.39M)
13. How many grams of bromine, Br2, are needed to prepare 0.500 L of a 0.0100M solution in water?