Solutions Test Review
Explain the relationship between solvent, solute, and solution.
Define homogenous, heterogenous, colloids, suspensions, miscible, immiscible, electrolyte, and non-electrolyte.
Explain the relationship between bond types and solubility.
What factors impact the solubility of a gas?
What factors impact the solubility and rate of solution of solids in a liquid?
Define dilute, concentrated, saturated, and supersaturated.
Explain the following solution units: molarity, molality, and normality.
What is the molarity and normality of 2.1 L of solution with 212.6 g H2SO4 dissolved in it?
Explain how to create 3 molal NaCl.
Explain how to make 4.2 L of 2 molar MgCl2.
How much 5 M H2SO4 is needed to react with 219 mL of 4 M LiOH?
What is the heat of solution if a 50 g water sample goes from 22 C to 19 C when 88 g HCl is dissolved?
Solutions Test Review
Explain the relationship between solvent, solute, and solution.
The solute is dissolved by the solvent to make the solution
Define homogenous, heterogenous, colloids, suspensions, miscible, immiscible, electrolyte, and non-electrolyte.
Homogenous – thoroughly, evenly mixed, solute & solvent are in the same phase
Heterogenous – not mixed evenly, solute & solvent are in different phases
Colloids – large particles which do not dissolve, but stay mixed
Suspensions – large particles which settle after stirring
Miscible – parts dissolve into each other & stay mixed
Immiscible – parts do not dissolve into each other, they may temporarily mix, but will separate (oil &
water)
Electrolyte – a solute that will conduct electricity when dissolved
Non-electrolyte – a solute that will not conduct electricity when dissolved
Explain the relationship between bond types and solubility.
Solute and solvent must have the same bond type
Polar dissolves in polar, non-polar in non-polar. (Like dissolves like)
What factors impact the solubility of a gas?
Pressure & temperature
Pressure pushes gas back into the solution, increasing solubility
Temperature increases energy, bonds break between gas and solvent, solubility of gas decreases
What factors impact the solubility and rate of solution of solids in a liquid?
Solids are more soluble in warm solvent
Increasing temp, agitation, and surface area will increase rate of solubility
Define dilute, concentrated, saturated, and supersaturated.
Dilute – little solute dissolved
Concentrated – a lot of solute dissolved
Saturated – the maximum solute dissolved at the given temperature
Supersaturated – more solute dissolved than the amount that can be dissolved at that temperature
Explain the following solution units: molarity, molality, and normality.
Molarity (M) – moles of solute/liter of solution
Normality (N) – moles of H+ or OH-/liter of solution
Molality (m) – moles of solute/kg solvent
What is the molarity and normality of 2.1 L of solution with 212.6 g H2SO4 dissolved in it?
(212.6 g H2SO4 /2.1 L)(1 mol H2SO4 /98.08 g H2SO4) = 1.03mol H2SO4 /L = 1.03 M H2SO4
(1.03mol H2SO4 /L)(2 mol H+/1 mol H2SO4) = 2.06 mol H+/L = 2.06 N H2SO4
Explain how to create 3 molal NaCl in water.
(3 mol NaCl/1 kg water)(58.44 g NaCl/1 mol NaCl) = 175.32 g NaCl/1 kg water)
dissolve 175.32 g NaCl in 1 kg water
Explain how to make 4.2 L of 2 molar MgCl2.
(2 mol MgCl2/L)(4.2L)(95.21 g MgCl2 /mol MgCl2) = 799.62 g MgCl2
dissolve 799.76 g MgCl2 in 2.1 L water, then add water until you have 4.2 L of solution
How much 5 M H2SO4 is needed to react with 219 mL of 4 M LiOH?
2 LiOH + H2SO4 -> Li2SO4 + 2H2O
(219 mL LiOH)(1L/1000mL)(4 mol LiOH/1L)(1 mol H2SO4 /2 mol LiOH)(1L/5 mol H2SO4) = .088 L or 88
mL
What is the heat of solution if a 50 g water sample goes from 22 C to 19 C when 88 g HCl is dissolved?
(88 g HCl)(1 mol HCl/36.46 g HCl) = 2.41 mol HCl
(4.18J/1g H2O 1C)(50 g H2O)(-3 C) = -623.7J or -.6237 kJ
Heat of Solution = kJ/mol
-.6237 kJ/2.41 mol -.26 kJ/mol