Chapter 14 Quizes

14-2:  Molality

  1. Calculate the molality of a solution containing 112g CH3OH in 134mL of water.  The density of water is 1.0g/mL.  The molecular weight of CH3OH 32.0g/mol.

 

 

 

  1. Calculate the molality of all ions by adding 1.4g NaCl to 75mL of water.  Use the following equation.  NaCl(s) à Na+(aq) + Cl-(aq)

 

 

 

  1. Calculate the molality of the Br- ion by adding 2.2g MgBr2 to 100mL of water.  The molecular weight of MgBr2 is 184.1g/mol.

 

 

 

  1. How many milliliters of water is required to prepare a 32.6m solution from 78g of CaCl2?  The molecular weight of CaCl2 is 112g/mol.

 

 

 

  1. What mass of KBr should be added to 120mL of water to create a 1.8m solution?  The molecular weight of KBr is 119g/mol.