Chapter 4 + Silver Salts Lab

Chemical Reactions describe

chemical changes

Chemical Equations

depict chemical reactions

Reactants

substances on the left side of the chemical equation

Products

substances on the right side of the chemical equation

Stoichiometry

numerical relationship between the balancing coefficients; ratios of the coefficients

Molar Ratio

ratio between stoichiometric coefficients

Limiting Reactant

reactant that limits the amount of product

Theoretical yield

amount of product produced when all of limiting reactant is consumed

Actual yield

what is actually produced

Percent yield

percentage of theoretical yield obtained; actual yield / theoretical yield * 100%

Excess Reactant Remaining can be calculated by

difference between initial mass and amount consumed

Gravimetric Analysis

method for determination of mass of an analyte based on mass of a solid

Precipitation Reaction

a reaction that produces a solid from reaction of two liquid solutions

Precipitate

insoluble solid from precipitation reaction

Aqueous Solution

solution of water as solvent with dissolved solvent

Hydration

ionic compounds in aqueous state break up into separate ions surrounded by water

Strong Electrolytes

compounds that fully dissociate into ions; good at conducting electricity

Strong Electrolyte Examples

NaCl, strong acids/bases

Weak Electrolytes

compounds that partially dissociate into ions

Weak Electrolyte Examples

weak acids and bases

Non-Electrolytes

compounds that do not dissociate

Non-electrolyte examples

AgCl; AgCl; solids

Double Replacement/Metathesis reaction

a reaction where molecules switch bonding partners

Molecular Equation

shows the complete neutral formulas for everything as molecules

Total Ionic Equation

lists all ions present (reactant and product); insoluble salts are not broken apart since not ions

Spectator Ions

species that appear unchanged on both sides of the equation; do not participate in reaction

Net Ionic Equation

shows only species that change during reaction; no spectator ions

What instrument do you use to measure a fixed volume amount?

volumetric pipet

What instrument do you use to measure a varied amount of a liquid?

buret

What instrument do you use to measure an approximate liquid amount?

graduated cylinder

What would the graph of amount of product vs. reactant look like for a precipitation reaction and why?

linear then level off bc direct relationship and constant variable (other reactant) would become limiting at one point so only a certain amount of product can form

Concentration

measures the amount of solute relative to solvent

Dilute Solutions

small amount of solute relative to solvent

concentrated solutions

large amount of solute relative to solvent

Molarity

amount of solute (in moles) per volume of solution (in L)

Molarity equation

amount of solute (in moles) / volume of solution (in Liters)

How can you dilute a solution?

by adding more solvent

Do you dilute the whole solution?

no

The portion of the concentration solution has a

set amount of moles

Diluting a part of the solution puts 

the number of moles in a greater volume; lowers the concentration

Molarity & Diluting Equation

M₁V₁ = M₂V₂

M₁

molarity of stock

V₁

volume of stock

M₂

molarity of desired solution

V₂

volume of desired solution

What do you use to create a solution of chosen volume and concentration?

a concentrated stock