Solutions : FreezePtDepression (20 Variations) It takes 6.86 kg of ethylene glycol (antifreeze) to decrease the freezing point of 6.50 kg of water to -25.0oF (-31.7oC). How much sodium chloride (NaCl) would it take to decrease the freezing point of 6.50 kg of water to -25.0oF? (Assuming all the salt will dissolve in that amount of water.)
Solutions : SolutionNanoPics (4 Variations) The drawings below represent flasks of aqueous solutions. Each pink dot represents a dissolved solute particle. Which of the following solutions is most concentrated?
Solutions : ReverseOsmosis (20 Variations) You are given a water sample that contains ammonium chloride (NH4Cl). You determine the concentration of the salt to be 0.500 M and decide to purify the water using reverse osmosis. What is the minimum pressure that must be applied at 30.0oC to force the water through the membrane?
Solutions : SolnPrepByDilution (10 Variations) For the analysis of trace metals it is necessary to prepare solutions of very low concentrations from a stock solution of higher concentration using a micropipet and a volumetric flask. What volume of a 0.0010 M solution of Zn(NO3)2 (aq) would be required to prepare a 5.0 nM solution of Zn2+ in a 250mL flask?
Solutions / Solvents |
Chemometrics
Solutions : SolnPrepByMass (4 Variations) You are required to prepare 5 L of a solution containing 1.000 x 10-3 mol/L of Cu2+(aq). Which of the following procedures would produce an appropriate solution?
Solutions : ConvertConcUnits (10 Variations) The maximum concentration of arsenic in drinking water that is allowed by the EPA is 0.050 mg/L. Express this as a weight percent. (You can assume the density of the water solution is 1.0g/mL.)
Solutions : WtPercentToMolarity (4 Variations)
A common concentration unit used commercially is percent weight per volume (%W/V) which is the number of grams of solute in 100 mL of solution. A bottle of vinegar contains 5 %W/V acetic acid (CH3COOH). What is the molar concentration of acetic acid in the vinegar?
Solutions / Solvents |
Nomenclature / Units / Symbols |
Chemometrics
Solutions : CalcMolarityFromPPT (10 Variations) You are given a water sample to analyze from a lake contaminated with lead. It takes 24 mL of 0.020 M NaCl to exactly precipitate the Pb2+ ions from 61 mL of the water sample. What is the concentration of Pb2+ ions in the water? Pb2+(aq) + 2NaCl(aq)PbCl2(s) + 2Na+(aq)
PbCl2(s) + 2Na+(aq)
