I have to write out a lab plan for an upcoming experiment! andcomplete the table below

Experiment 9: Introduction to Acids, Bases, and pH Learning

Objectives

» to gain experience with a wide variety of acids and bases

» to learn how to predict the principal species in asolution

»to learn how to measure acidity, basicity, and pH

» to predict what will happen when different acid and basesolutions are mixed

Be sure to record all data in your own notebook. Materials Lotsof acids and bases in various concentrations, litmus paper, wellplates and pH meters.

Introduction to Acids and Bases Acids and bases are all aroundus. They are present in the fruits and vegetables we eat, in thesodas we drink, and in the various commercially available productsthat we use to unclog our kitchen sinks! Acids are characterizedwith respect to their ability to produce hydronium ions (H3O + ).Bases are characterized with respect to their ability to producehydroxide ions (OH– ). Both acids and bases can be classified as“strong” or “weak,” which are allusions to whether the species is astrong electrolyte (placing many ions in solutions, see (1) below)or a weak electrolyte (placing a small number of ions in solution,see (2), below). (1) HCl(aq) + H2O()  H3O + (aq) + Cl (aq)Production of hydronium ion by a strong acid (2) NH3 (g) + H2O()NH4 + (aq) + OH (aq) Production of hydroxide ion by a weak baseStrong acids produce large amounts of hydronium ions because theirreaction with water goes essentially to completion, thus producinga stoichiometric number of ions. Weak acids react with water in thesame type of proton-transfer process, but the equilibrium constantis not as large and only a minimal number of ions are created. Thesame can be said for strong and weak bases with respect to theamount of hydroxide formed. The chemical structure of the acid orbase plays a large role in its ability to lose or attract a proton.9-2 Introduction to Acids, Bases and pH In order for you to predictthe principal species in solution, you must know if a particularacid or base is strong or weak. It is best to just memorize thestrong ones: Strong Acids HCl hydrochloric acid HBr hydrobromicacid HI hydroiodic acid HNO3 nitric acid HClO4 perchloric acidH2SO4 sulfuric acid Strong Bases NaOH sodium hydroxide KOHpotassium hydroxide Strong acids and strong bases are strongelectrolytes; their principal species in solution are the fullydissociated ions – H3O + , Br– NO3 – , ClO4 – , HSO4 – , Na+ , K+ ,OH– , etc. IT IS CRITICAL THAT YOU MEMORIZE THE NAMES AND FORMULASOF THESE STRONG ACIDS AND BASES AND ALSO KNOW WHAT IONS THEYPRODUCE. DO IT NOW. Pretty much anything else that has a name thatends with “acid” – hydrofluoric acid, acetic acid, formic acid,nitrous (rather than nitric) acid, phosphoric acid, etc. – is aweak acid. Just about anything else containing nitrogen in it is aweak base. Weak acids and weak bases are weak electrolytes. Theirprincipal species in solution is just themselves. The lower the pHof a solution, the more acidic it is. Conversely, the higher the pHof a solution, the more basic it is. A pH of 7 indicates that theconcentrations of H3O + and OH– are equal; such solutions arecalled “neutral.” Acids and bases react with each other to formneutral solutions with salts and water as the products. (Can youwrite the reaction equation between HCl and NaOH?) Salts insolution will also form acidic, basic or neutral solutionsdepending on the properties of the ions. This will be apparent insome of the work carried out in today’s experiment.

Procedures Part 1: Acid, Base, or Neutral?

Types of substances in this table include neutral salts, strongacids, strong bases, weak acids (might be a salt), and weak bases(might be a salt). Water is present in large quantities in anyaqueous system, so you need not list H2Omolecules as a principalspecies.

Solution Type of Substance Principal Specie(s) in SolutionPrediction Measured pH

a 0.1 M HCl Strong acid H3O + , Cl– acidic

b 0.1 M H3PO4 Weak acid

c 0.1 M CH3CO2H Weak acid

d 0.1 M NH4Cl Salt (acidic) NH4 + , Cl–

f 0.1 M NaCl Salt (neutral) Na+, Cl– neutral

g 0.1 M NaO2CCH3 Salt (basic)

h 0.1 M NH3 Weak base NH3

i 0.1 M NaOH Strong base

When you get to lab, discuss your predictions with your partnerand try to come to a consensus on your best guesses. Then measurethe pH of each solution using a pH meter (Read the pH Meter BluePages! The use of these meters will also be demonstrated for you.)Record your predictions and observations in tabular form in yournotebook. Note any surprises, as you will need to explain themlater!