Colligative Properties Test Review
Compare & contrast ionic and net ionic equations
Write the ionic and net ionic equations for the following reactions:
1. FeSO4 + BaCl2 -> FeCl2 + BaSO4
2. AgNO3 + BaCl2 -> AgCl + Ba(NO3)2
3. FeSO4 + NaCl -> FeCl2 + Na2SO4
Define spectator ion and identify the spectator ions for each of the three reactions listed above.
Define dissociation and explain which types of compounds will dissociate.
How can we tell it an ionic compound does not dissociate?
How are strong and weak electrolytes associated with dissociation?
What is happening at the molecular level that causes a solute to elevate the boiling point of a solvent?
Which compound will depress the freezing point of water the most - PbCl2, NaCl, or KCl? Why?
Which compound will elevate the boiling point of water the most - Ni(NO3)2, NH4ClO3, or (NH4)3PO4?
What will the new boiling point be if 121 g FeCl3 is dissolved in 1,201 mL water?
(+.51 °C/m)
What will the new freezing point be if 45 g NaCl is dissolved in 121 mL water?
(-1.86 °C/m)
Colligative Properties Test Review
Compare & contrast ionic and net ionic equations
Both show the ions involved in a reaction. Net Ionic only shows those that changed during the reaction
Write the ionic and net ionic equations for the following reactions:
1. FeSO4 + BaCl2 -> FeCl2 + BaSO4
Fe+2 + SO4-2 + Ba+2 + 2Cl- -> Fe+2 + 2Cl- + BaSO4
SO4-2 + Ba+2 -> BaSO4
2. 2AgNO3 + BaCl2 -> 2AgCl + Ba(NO3)2
2Ag+ + 2NO3- + Ba+2 + 2Cl- -> 2AgCl + Ba+2 + 2NO32Ag+ + 2Cl- -> AgCl
3. FeSO4 + 2NaCl -> FeCl2 + Na2SO4
Fe+2 + SO4-2 + 2Na+ + 2Cl- -> Fe+2 + 2Cl2- + Na+ + SO4-2
No Net Reaction
Define spectator ion and identify the spectator ions for each of the three reactions listed above.
Spectator ion does not change during reaction
1- Fe+2, Cl2- Ba+2, NO33- all ions are spectators
Define dissociation and explain which types of compounds will dissociate.
Dissociation is splitting into ions when dissolving. Ionic compounds will dissociate.
How can we tell it an ionic compound does not dissociate?
If it does not dissolve, it does not dissociate.
How are strong and weak electrolytes associated with dissociation?
Dissociation is breaking into ions. Strong electrolytes dissociate a lot, weak electrolytes don’t’ dissociate
much
What is happening at the molecular level that causes a solute to elevate the boiling point of a solvent?
Attractions between the solute and solvent molecules hold the solvent and keep it from boiling at its
normal temperature. Higher temperatures are needed to break the new solvent-solute attractions
Which compound will depress the freezing point of water the most - PbCl2, NaCl, or KCl? Why?
NaCl or KCl. PbCl2 does not dissolve, so it will not impact the boiling point. Both NaCl and KCl will
dissociate into 2 particles, so they have the same impact on boiling point.
Which compound will elevate the boiling point of water the most - Ni(NO3)2, NH4ClO3, or (NH4)3PO4?
(NH4)3PO4 because it breaks into the most particles (4).
What will the new boiling point be if 121 g FeCl3 is dissolved in 1,201 mL water? (+.51 °C/m)
(121 g FeCl3 /1,201 ml water)(1 mol FeCl3 / 162.2g FeCl3)(1000 mL water/ 1 L water)(1 L water/1 Kg
water)
= .62 m FeCl3 (4 m particles/1 m FeCl3)(+.51 C/1 m particles) = 1.26 C
new BP = 101.26 C
What will the new freezing point be if 45 g NaCl is dissolved in 121 mL water? (-1.86 °C/m)
(45 g NaCl/121 mL water)(1 mol NaCl/58.44 g NaCl)(1000 mL water/ 1 L water)(1 L water/1 Kg water) =
6.36 m NaCl (2 m particles/1 m NaCl)(-1.86 C/1 m particles) = -23.66 C