Chemistry

Module 4:
10.
Strong Bases: NaOH, KOH, Na2CO3, NaHCO3, Na3PO4, NaHPO4,
Strong Acids: Fe(NO3)3, HCL, HNO3, Al(NO3)3, NiCl2, H2SO4
11.
Acidic Neutral Basic
NaCl KNO3 NaOH
HC2H3O2 Na2CO3
NaC2H3O2 NaHCO3
Fe(NO3)3 NaNO3 Na3PO4
HCl MgSO4 KOH
HNO3 Na2SO4 NaHPO4
CuSO4 NaNO2
CoCl2
Al(NO3)3
NiCl2
H2SO4
KCl
NH4Cl
12.
CuSO4
CuCO3.Cu(OH)2(s) + 2 H2SO4(aq) ----> 2 CuSO4(aq) + CO2(g) + 3 H2O(l)
Na3PO4
Na3PO4 (aq) + 3H2O (l) --> H3PO4 (aq) + 3NaOH (aq)
13.
Arrhenius definition says that a base yields the hydroxide ion (OH-) in an aqueous solution. Arrhenius definition is dependent on substances in aqueous solutions. On the other hand, a Bronsted-Lowry base is one that accepts a proton (hydrgoen ion, H+; since hydrogen donates its only one electron in order to be H+ which is just a bare proton) from a proton donor which is the Bronsted-Lowry acid. Bronsted-Lowry definition goes beyond those substances in aqueous solutions. It can identify a substance whether it's an acid or a base even if this substance is not in water.
14.
In this system, an acid is defined as any chemical species (molecule or ion) that is able to lose, or "donate" a hydrogen ion (proton), and a base is a species with the ability to gain or "accept" a hydrogen ion (proton). acid salt: NaHSO4 & H2O => Na+ & H3O+ & SO4-2

basic salt: Na2CO3 & H2O => 2Na+ & (HCO3)-1 & OH-

neutral salt: NaCl & H2O => Na+ & Cl- & H2O
Module 5- Buffers
15.
An acid contributes a surplus of hydrogen ions to a solution. A base contributes a surplus of hydroxide (OH) ions to a solution.
16.
Buffer solutions are solutions that resist change in Hydronium ion and the hydroxide ion concentration (and consequently pH) upon addition of small amounts of acid or base, or upon dilution. Buffer solutions consist of a weak acid and its conjugate base (more common) or a weak base and its conjugate acid. This is an appropriate name because the solution ‘’buffs’’ solutions to keep the correct pH for enzymes to work.
17. The pH decreased when acid was added to the A2 and then the A3. This is because
The buffer solution must remove most of the new hydrogen ions otherwise the pH would drop markedly. This is what happens: HA- + H+  A- + H2O
18. The pH value of B2 and B3 increased when base was added. The pH rises rapidly because you have far exceeded the buffer capacity of your buffer and have free strong base so the pH is calculated directly from its concentration
OH-(aq) + HA(aq) --> H2O(l) + A-(aq)
19. Acidic buffers comprise of a weak acid and its salt. eg. ethanoic acid and sodium ethanoate. Basic Buffers comprise of a weak base and its conjugate salt. eg. aqueous ammonia and ammonium chloride.

Individual Portion:
20. HCl completely ionizes into H+ and Cl- in water, or any aqueous solution. The H+ is what reacts with other chemicals. HCl can create very acidic pH's. Acetic acid on the other hand has a ph closer to neutral (where half of the carbonic acid molecules are ionized and half are not) therefore is not as dangerous.
21. H3PO4 liberates a hydrogen ion:

H3PO4 = H(+) + H2PO4(-)

But less than 1% of the phosphoric acid is actually broken apart into ions. The rest of it is swimming around in aqueous solution completely intact. That's why we call it a weak acid.
22.
sodium chloride (NaCl) is a common salt that, when dissolved in water, breaks into the Na+ ion and the Cl- anion. Both the sodium ion and the chloride anion are toxic to macros because they disrupt the organism osmoregulation system. It is therefore harmful to an environment.
Buffer Solution reaction with acid:
CH3COO-(aq) + H^+(aq)  CH3COOH (aq)
Buffer solution reqaction with base:
CH3COOH(aq) + OH-(aq)  CH3COO-(aq) + H2(l)