DETERMING CONCENTRATIONS OF SOLUTIONS

MOLAR Molar is mol solube/1 L solution Making molar solution 1)Add ½ of the total solvent 2)Add required amount of solute 3)Add water until final volume of solution

MAKE 2 L OF 3 M SODIUM CHLORIDE Determine how much NaCl is needed (3 mol NaCl/1 L solution) * 2 L solution = 6 mol NaCl (6 mol NaCl) * (58.44 g NaCl/1 mol NaCl) = g NaCl Mix solution 1)Add 1 L water to beaker or flask 2)Add g NaCl and stir until dissolved 3)Add water until there is exactly 2 L of solution

MAKE 1.7 L OF 2 M SODIUM CHLORIDE Determine how much NaCl is needed (2 mol NaCl/1 L solution) * 1.7 L solution = 3.4 mol NaCl (3.4 mol NaCl) * (58.44 g NaCl/1 mol NaCl) = g NaCl Mix solution 1)Add.9 L water to beaker or flask 2)Add g NaCl and stir until dissolved 3)Add water until there is exactly 1.7 L of solution

DETERMINING THE CONCENTRATION Molar is mol solute/L solution Determine concentration 1)Determine how many moles of solute 2)Divide by total liters of solution

WHAT IS THE CONCENTRATION? What is the concentration if g NaCl is dissolved in 2.2 L of solution? 1)Determine moles of NaCl g NaCl (1 mol NaCl/58.44 g NaCl) =.74 mol NaCl 2) Divide moles by volume.74 mol NaCl/2.2 L solution =.34 M NaCl

WHAT IS THE CONCENTRATION? What is the concentration if g NaCl is dissolved in 2.7 L of solution? 1)Determine moles of NaCl g NaCl (1 mol NaCl/58.44 g NaCl) = 1.67 mol NaCl 2) Divide moles by volume 1.67 mol NaCl/2.7 L solution =.62 M NaCl

HOW MANY GRAMS? How much NaCl is in 2 L of 4 M NaCl? It’s all dimensional analysis (4 mol NaCl/1 L solution)(2 L solution)(58.44 g NaCl/1 mol NaCl) = g NaCl

HOW MANY GRAMS? How much NaCl is in 617 mL of 3.5 M NaCl? (3.5 mol NaCl/1 L solution)(617 mL solution)(1 L solution/1000 mL solution)(58.44 g NaCl/1 mol NaCl) = g NaCl

HOW MANY GRAMS? How much NaCl is in 617 mL of 3.5 M NaCl? (3.5 mol NaCl/1 L solution)(617 mL solution)(1 L solution/1000 mL solution)(58.44 g NaCl/1 mol NaCl) = g NaCl

DILUTING A SOLUTION Adding water to a solution dilutes it, reducing the concentration A new concentration of a diluted solution is found using the following formula C1V1 = C2V2 C1 = original concentration V1 = amount of original solution C2 = new concentration V2 = new volume (original solution volume + volume of water added)

What is the new concentration if 10 mL of 4M NaCl is combined with 40 mL of water? C1V1 = C2V2 (4M)(10 mL) = C2(50 mL) C2 =.8M NaCl