a) Circle the correctresponse or fill in the blanks . What is the approximate pH
ID: 75936 • Letter: A
Question
a) Circle the correctresponse or fill in the blanks .
What is the approximate pHof a 10-9 Msolution of HCl 3 5 7 9
Which is a weak acidHNO2 HClO4 HNO3 HCl H2SO4
Which is the strongestbase ClO- Cl- ClO4- CaCl2
Which acid would be mostsuited to making a buffer with a pH = 4.
CH3COOH pKa =4.74 , HCOOHpKa = 3.74 , NH4 + PKa = 9.26 ,
b) Classify the followingas acidic A, basic B, or neutral N
CH3NH2 _____NaNO3 ______ Na(CH3COO) ________ NH4Cl _______
c) Give the conjugate acidof sulfate ion SO42- ____________ and the conjugate base ofC4H8O2 __________.
d) The Kafor HCN is 5 x 10-10 what isKb for the cyanideion? ________________________
Explanation / Answer
Circle the correctresponse or fill in the blanks .
What is the approximate pHof a 10-9 Msolution of HCl 3 5 7 9; the pH ~ 7 (recallneutral water has [H+] ~ 7 already, so the additi0nal 1e-9 will notmatter much)
Which is a weak acidHNO2 HClO4HNO3HCl H2SO4
HNO2 is the weakacid
Which is the strongestbase ClO- Cl-ClO4-CaCl2
ClO- is the strongest base, because its conjugateacid HClO is a weak acid. All the other conjugate bases listed inthe question have strong conjugate acids.
Which acid would be mostsuited to making a buffer with a pH = 4.
CH3COOH pKa=4.74 , HCOOH pKa = 3.74 , NH4 +PKa = 9.26 ,
HCOOH. Buffers are madebest at pH's when pH ~ pKa. 3.74 is the closest here
b) Classify the followingas acidic A, basic B, or neutral N
CH3NH2__base___ NaNO3_neutral_ Na(CH3COO)__base______ NH4Cl _ acid (NH4+ is acid)__
c) Give the conjugate acidof sulfate ion SO42-__HSO42-_____ andthe conjugate base of C4H8O2 __C4H7O2___.
d) The Kafor HCN is 5 x 10-10 what isKb for thecyanide ion?
Ka*Kb = 1e-14
Kb = (1e-14)/5e-10 = 2e-5
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.