Nature of Solutions (chapter 5 and 7.1) Flashcards
(50 cards)
What two parts make up a solution?
Solute and solvent
What is a solute?
The thing being dissolved in a solution.
What is a solvent?
The thing doing the dissolving (solute dissolved in). (eg. water)
What does the level of conductivity in a solution depend on?
It depends on how many ions are present in the solution.
What is a strong electrolyte? How many solute particles break apart into ions? Name 3 things that this includes.
A solution that conducts electricity very efficiently. (aq)
- all solute particles break apart into ions (high solubility)
- includes strong acids, strong bases, and soluble salts
What is a weak electrolyte? How many solute particles break apart into ions? Name 2 things that this includes.
A solution that conducts electricity only slightly.
- Few solute particles create ions
- includes weak acids and weak bases
What is a nonelectrolyte? How many solute particles break apart into ions? Name something that this includes.
A solution that does not conduct electricity.
- No solute particles create ions
- includes soluble but nonionic compounds (eg. sugar, ethanol)
What is the VESPR shape of water? What angle does this shape form?
It is bent/angular/v-shaped, forming a 105 degree angle.
Why can water dissolve many substances?
Because of its polarity (oxygen is the slightly negative end because of its higher electronegativity, and hydrogen is the slightly positive end).
What is hydration? Explain water’s attraction to cations/anions.
Hydration is the interaction between the dissolving molecules and water molecules. Positive ends of water molecules are attracted to anions, and the negative ends of water molecules are attracted to cations.
What is dissociation? Do ionic compounds dissolve completely?
Dissociation is when an ionic compound dissolves in water and breaks into cations and anions. Ionic compounds do not all dissolve completely because of attractions between different ions/attraction between ions and water molecules.
Describe the part of Arrhenius’ theory about bases.
- bases are all hydroxide compounds
- bases dissociate into cations and OH
- OH is responsible for basic properties
- OH reacts with H to form water
Describe the part of Arrhenius’ theory about acids.
- acids only appear when hydrogen containing compounds dissolve in water (aq)
- dissociates into H and negative ions
- H responsible for acidic properties
Can water dissolve substances that don’t create ions?
Yes
What is ionization?
When a neutral atom or molecule is changed to an ion (assumed water solvent).
Discuss “like dissolves like” using water.
Molecules with an O-H bond like water, dissolve in water because of polarity. Nonpolar substances (eg. fat) do not dissolve in water. Nonpolar dissolves nonpolar and polar dissolves polar.
What is concentration?
The ratio that compares the quantity of solvent and quantity of solute.
When both substances in a solution are liquid, which is the solvent, and which is the solute?
The one with the largest volume is the solvent.
Percent by volume
- can be shown as % V/V (mL/100mL)
- percent by volume of the solute per volume of solution
- % volume = volume of solute / volume of solution x 100
Percent by mass/volume
- can be as % m/v (g/100mL)
- percent by mass of solute per volume of jump
- % mass/vol = mass of solute / volume of solution x 100
Percent by mass
- can be shown as % m/m (g/100g)
- percent by mass of solute per mass of solution
- % mass = mass of solute / mass of solution x 100
Parts per million
- special case of % mass
- % m/m x 10^6
- 1 ppm = 1 mg / kg
Amount concentration
C = n / v
- C - mol/L
- n - mol
- v - L
True or false: all ionic compounds are strong electrolytes.
True
