Chemistry Chapter 14 Homework
restate the bronsted-lowry definitions of acids and bases and demonstrate the definition with a chemical equation
A bronsted-lowry is a proton (H+) donor HCl(aq) + H20(l) → H30+(aq) + Cl-(aq) a bronsted-lowry base is a proton acceptor NH3(aq) + H2O(l) → NH4+(aq) + OH- (aq)
what is a buffer?
A buffer is a solution that will resist a change in pH as the weak acid can react with added base and the conjugate base can react with added acid (has to be able to act as a base and bond with the hydrogen ion, so pH doesn't change in an acid)( and act as an acid in a base so it can bond with the OH ion)(need to be weak to stay bonded)
according to the bronsted-lowry definition of acids and bases, what is a conjugate acid-base pair? Provide an example
A conjugate acid-base pair is when two substances differ only by a single proton (H+). An example of a conjugate acid-base pair is H20 and H30+
what are monoprotic and diprotic acids?
A monoprotic acid contains only 1 hydrogen ion that will dissociate in solution. A diprotic acid contains 2 hydrogen ions that will dissociate in solution.
what is the difference between a strong acid and a weak acid?
A strong acid will completely dissociate into component ions in solution to form a strong electrolyte. A weak acid will partially dissociate into component ions in solution to form a weak electrolyte.
what is the difference between a strong base and a weak base
A strong base will completely dissociate into component ions in solution to form a strong electrolyte. A weak base will react with water to a small extent to form a weak electrolyte solution of the hydroxide ion.
what is titration? What is the equivalent point?
A titration is a laboratory procedure in which a reactant of known concentration reacts with another of unknown concentration. THe volume of each solution are carefully monitored until the equivalence point is reached, usually when an indicator causes the reaction mixture to change colors. The equivalence point is experimental point when an exact stoichiometric amount of each reactant has been added.
restate the Arrhenius definition of an acid and demonstrate the definition with a chemical reaction
An Arrhenius acid produces H+ in aqueous solutions. HCl(aq) → H+(aq) + CL-(aq)
restate the Arrhenius definition of a base and demonstrate the definition with a chemical equation
An Arrhenius base produces OH- ions in aqueous solutions. NaOH(aq) → Na+ (aq) + OH-(aq)
what is an acid-base neutralization reaction? Provide an example
An acid base neutralization reaction is when the hydrogen ion form the acid reacts with the hydroxide ion from the base to form water HCl(aq) + NaOH(aq) → H20(l) + NaCl (aq)
what is the main component of stomach acid? Why do we have stomach acid?
The main component of stomach acid is hydrochloric acid. The role of acid in our stomach is to kill bacteria and start breaking down food.
what are the properties of acids? List some foods that contain acids
The properties of acids are Sour taste The ability to dissolve many metals Turn litmus paper red Some foods - lemon,limes and tomatoes
what are the properties of bases? Provide examples of common substances that contain bases
The properties of bases are Bitter taste Slippery feel Turn litmus paper blue Products containing bases- drano, baking soda, and antacids for acid indigestion
how is the strength of an acid related to the strength of it conjugate base?
The stronger the acid the weaker the conjugate base is, vice versa.
does pure water contain any H₃O+ ions? Explain
Yes, pure water contains H₃O+ because of the process of self-ionization.
identify each substance as an acid or a base and write a chemical equation showing how it is an acid or a base according to the arrhenius definition
a.) Ca(OH)₂(aq) - base ; Ca^2+(aq) + 2OH- b.) HC₂H₃0₂(aq) - acid ; H+ (aq) +C₂H₃0₂- (aq) c.) KOH(aq) - base ; K+(aq) + OH-(aq) d.) HNO₃(aq) - acid ; H+(aq) + NO₃-(aq)
identify each substance as an acid or a base and write a chemical equation showing how it is an acid or a base according to the Arrhenius definition
a.) H₂SO₄(aq) - Acid ; H+ (aq) + HSO₄^-(aq) b.) Sr(OH)₂(aq) - Base ; Sr2+(aq) + 2OH-(aq) c.) HBr(aq) - Acid ; H+(aq) + Br-(aq) d.) NaOH(aq)- Base ; Na+(aq) + OH-(aq)
give a possible value of [OH-] and [H₃O+] in a solution that is: a; acidic, b; basic and c; neutral
a.) [H₃O+] > 1.0x10^-7 and [OH-] < 1.0x10^-7 b.) [H₃O+] < 1.0x10^-7 and [OH-] > 1.0x10^-7 c.) [H₃O+] = 1.0x10^-7 and [OH-] = 1.0x10^-7
how is pH defined? A change of 1.0 pH unit corresponds to how much of a change in [H₃O+]?
pH= -log [H₃O+] ; A one unit change in pH corresponds to a 10x change in [H₃O+]
