Chapter 4 Flashcards
what are solutions composed of (2 things)
- solutes
- solvents
solutes
the substances present in smaller amounts, and the component that is dissolved
solvent
the substance present in a larger amount, and the component that is able to dissolve things
solution
a homogenous mixture of 2 or more substances, composed of a solvent and solutes
covalent bond
a bond made between atoms that are sharing their electrons
non-polar covalent bond
the electrons in the atoms are being evenly distributes
polar covalent bond
when the pulling power of one atom is stronger, and the electrons are displaced closer to that atom than the other
why is water a powerful solvent
water is polar, making it a powerful solvent
hydration
the process by which an ion is surrounded by H2O molecules arranged in a specific manner
ionic theory of solutions (Arrhenius)
certain substances (electrolytes and non-electrolytes) produce freely moving ions when they dissolve in water, and these ions conduct an electric current in solution
theoretically, if an electric wire is dipped into a solution of NaCl, how will electricity be conducted
- Na+ ions are attracted to the negative wire
- Cl- ions are attracted to the positive wire
- opposite charges allow an electrical current to flow through
what was the most important idea of Arrhenius’s ionic theory of solutions
- salt and pure water do not conduct electricity BUT
- once salts are dissolved in water, they are conductors
- salt contains ions even in the absence of an electric current
non-electrolyte
a substance that, when dissolved, results in a solution that does not conduct electricity
electrolyte
a substance that, when dissolved in water, results in a solution that can conduct electricity
strong electrolyte
100% dissociation
weak electrolyte
not completely dissociated
non-electrolyte
no cations or anions in the solution
basics of solubility rules
- substances vary in their solubility
- compounds that dissolve readily are said to be soluble
- compounds that dissolve very little are said to be insoluble
soluble
dissolves, aqueous
insoluble
does not dissolve, solid
molecular equation
a chemical equation in which the reactants and products are written as if they were molecular substances, even though they may actually exist in a solution as ions
examples of aqueous solutions that are written as compounds in molecular equations
AgNO3, NaCl, NaNO3
molecular and ionic equations
a chemical equation in which strong electrolytes are written as separate ions in a solution is a complete ionic equation. other reactants and products are written in molecular form
spectator ion
an ion in an ionic equation that does not take part in the reaction. it appears as both a reactant and a product
net ionic equation
an equation in which spectator ions are omitted. it shows the reaction that actually occurs at the ionic level
brief summary of writing net ionic equations (5 steps)
- write balanced molecular equation
- write the complete ionic equation showing the strong electrolytes
- determine precipitate from solubility rules
- cancel the spectator ions on both sides
- write the net ionic form