Unit 4 Flashcards
What is a solution?
A homogenous mixture of two or more substances
What is an aqueous solution?
A solution that contains water as the solvent
What is a heterogenous mixture?
A mixture that contains two or more phases, for example oil and water
What is a solute?
A substance that is dissolved in a solvent and is present in lower amount
What is a solvent?
The component of a solution that is present in the greatest amount
What is concentration?
The ratio of quantity of solute to solvent in a solution
What is a concentrated solution?
A high ratio of solute to solution
What is a dilute solution?
A low ratio of solute to solution
What is an alloy?
A solution of two or more metals
What is an amalgam?
An alloy of mercury and other metals
The formation of most solutions depends on the strength of 3 types of interactions. What are they?
Solute-solute particles, solute and solvent particles, solvent-solvent particles
When a solution forms, which particles are attracted to which?
The particles of solute are attracted to the particles of solvent
Which interactions must be disrupted when a solution forms?
Solvent-solvent and solute-solute interactions
What is the process of dissolving?
1) Forces between solute particles are disrupted (this step requires energy)
2) Forces between solvent particles are disrupted (this step requires energy)
3) There is interaction between solute and solvent particles (this step gives off energy)
What is known as a universal solvent? Why is it called this?
Water; it is a polar molecule, with two dipoles, which allows it to dissolve many things; it undergoes hydrogen bonding with itself
What is hydration?
The process in which water molecules surround ions
What is dissociation?
The separation of individual ions from an ionic compound as it dissolves in water
Do all ionic compounds dissolve in water?
No, if the attraction between both ions in the compound is too strong, the compound won’t dissolve and the crystal stays together
Finish the sentence:
The greater the charge on each ion…
The less soluble the compound will be
What does miscible mean?
Liquids that mix with each other to form a solution
What does immiscible mean?
Liquids that do not readily mix to form a solution
What is a surfactant?
A compound with a non-polar hydrophobic part and also a polar hydrophilic part
What is electrical conductivity?
The ability to conduct electrical current
What are strong, weak and nonelectrolytes?
Strong: many ions, great conductors
Weak: few ions, weak conductors
Nonelectronlytes: no ions, do not conduct at all
What are strong bases?
They completely ionize in water to produce a metal cation (Na+) and a hydroxide anion (OH-)
What is solubility?
The maximum amount of solute that will dissolve in a given quantity of solvent at a specific temperature
What is an unsaturated solution?
A solution in which more solute can dissolve
What is a saturated solution?
A solution that contains the maximum quantity of solute
What is a supersaturated solution?
A solution that contains more than the maximum quantity of solute it should contain
What does like dissolves like mean?
Solubility is favored when solute and solvent have similar properties
What is Henry’s law?
The amount of gas dissolved in a solution is directly proportional to the pressure of the gas above the solution
What is a solubility curve?
A graph of the solubility of a substance over a range of temperatures
What is the rate of dissolving?
A measure of how quickly a solute dissolves in a solvent
What is vapor pressure?
The pressure exerted by the vapor given off by a liquid
What is Raoult’s Law?
It allows us to calculate the vapor pressure of solutions
What do we call a solution that obeys Raoult’s Law?
An ideal solution
What is a stock solution?
A concentrated solution that is used to prepare dilute solutions for actual use
What is molar/amount concentration (c)?
The amount in moles of solute dissolved in 1 L of solution
What is the equation for molar concentration?
Molar concentration = amount of solute in moles/volume of solution in litres
What is a standard solution?
A solution for which the precise concentration is known
What is percent (V/V)?
A ratio of the volume of solute to the volume of solution expressed as a percent
What is percent (W/V)?
A ratio of the mass of solute (in grams) to the volume of solution (in mL) expressed as a percent
What is percent (W/W) or mass percent?
A ratio of the mass of solute to the mass of solution expressed as a percent
What is a mole fraction?
The ratio of the number of moles of a component divided by the total moles of solution
What is molarity?
The number of moles of solute per kilogram of solvent
What is normality?
The number of equivalents per liter of solution
What is the dilution equation?
C1V1 = C2V2
What are the steps to make a standard solution from a solid solute?
1) measure the amount of solid solute using a balance
2) dissolve the solute in water in a volumetric flask
3) add more water to the desired final volume
4) mix the solution
5) transfer solution to a WHMIS labeled container
What is a strong acid?
An acid that ionizes completely in water to form hydrogen ions
What is a weak acid?
An acid that partially ionizes in a water solution
What is a strong base?
An ionic substance that (according to Arrhenius) dissociates completely in water releasing hydroxide ions
What is a weak base?
A base that produces few hydroxide ions in water
What are acidic oxides?
Non-metal oxides form acids in water; their covalent bonds do not break apart in water
What are basic oxides?
Metal oxides form bases in water; their ionic bonds that dissociate in water
What is a Lewis acid?
An electron pair acceptor
What is a Lewis base?
An electron pair donor
What is a pH scale?
A scale named after the “potency of Hydrogen” used to describe the acidity or basicity of a solution
