Chapter 4 Flashcards
Solvent verses solute:
The solvent is the greater number of moles while the solute is the smaller number of moles.
Concentration:
The amount of solute in a solvent or solution
Mass to volume:
Such as mg/L or M (g/L)
What is a stock solution?
It is the concentrated form of a solution from a company which the scientist will use to create a diluted solution (M initial of V initial)
What does Beer’s Law say and what is its eqation?
It says that absorbance (A) is directly proportional to concentration (c).
A = Ebc Eb= slope
What is an electolyte?
It is a solute that imparts electrical conductivity to an aqueous solution. All Ions are electrolytes.
What is a strong electolyte?
A strong electrolyte may be a strong acid or a strong base.
A strong electrolyte disassociates completely into its ions.
What is a weak electrolyte?
A weak electrolyte is a compound in which not all of its molecules completely disassociate into its ions.
What are the Bronsten-Lowry definitions of acids and bases?
Acid is a proton donor
Base is a proton acceptor
Proton = H+ = H3O+
What is a neutralization reaction? How are this reaction’s products predicted?
It is an acid base reaction. This reaction produces a salt (metal + nonmetal) and water.
The products of this reaction switch negative partners and the cation is written first.
What don’t you do in an overall ionic equation?
You do not disassociate liquids or solids because they would not disassociate in an aq solution.
What is a strong acid? What are the strong acids?
Strong acids disassociate completely in water. They are determined by the amount of H+.
Hydrochloric acid: HCl, Hydrobromic acid: HBr, Hydroiodic acid: HI, Nitric acid: HNO3, Sulfuric acid: H2SO4, Perchloric acid: HClO4.
What is a strong base? How do you determine what is a strong base?
A strong base disassociates completely in water.
Strong bases are Group 1&2 elements plus hydroxide (OH-). (ie LiOH, Lithium Hydroxide)
Amphiprotic:
Compound capable of acting as a acid and a base (ie H2O with equal amounts of hydrogen and hydroxide ions)
What formulas are used for neuralization reactions and dilution reactions, how are they different, and why?
N: MaVa/coefficient = MbVb/coefficient
D: M1V1=M2V2
The neutralization reaction is divided by the coefficient because this reaction involves mole to mole.
What are the oxidation number (O.N.) Rules?
- In neutral molecule O.N. sum equals zero, in ion O.N. sum equals charge of the ion
- In each atom of a pure element O.N. equals zero
- In monatomic ion O.N. equals the charge on the ion
- Fluorine O.N. is -1 in all compounds
- Hydrogen O.N. = +1, Oxygen O.N. = -2 in most compounds
- Br and Cl O.N. numbers equal -1 unless combined with O or F
What are the diatomic molecules?
Fluorine, Nitrogen, Oxygen, Chlorine, Bromine, Iodine, Hydrogen, and Helium
What are the units of Molarity?
M= mol/L
What is the purpose of a titration?
To measure the volume of reactants, that is, to find an unknown concentration
What does a titrant do?
A titrant is used to neutralize a solution
What is a standard solution?
It is a solution of known concentration used as a titrant
What is the equivalence point of a titration?
When the number of moles of standard solution equals the number of moles of the unknown concentration
The equivalence point is the end point
What is the end point of a titration?
Point where indicator changes color, this occurs when the moles of unknown solution are consumed.
What is the end point of a titration?
Point where indicator changes color, this occurs when the moles of unknown solution are consumed.
