CHEM 1202 ACIDS & BASES LSU
Which of the following salts will produce a basic solution when dissolved in water? A)Ga(NO3)3 B)Li2SO4 C)BaO D)NH4NO3 E)SrBr2
C
What is the pH of 1M RbOH?
pH=14
What is the pH of 1x10^-3M HClO4?
pH=3
What is the pH of 1x10^-10M HNO3?
pH=7
What is the pH of the solution after 100mL of 2M KOH reacted with 100mL of 2M HSbF6 (pKa=-20)? Explain your answer.
pH=7. KOH is a strong base. HSbF6 is a strong acid, as indicated by its super negative pKa value. When equal amounts of strong acid and strong base react, they neutralize each other, and we are only left with the pH of water to account for.
CsOH is a strong or weak base?
strong
H2SO4 is a strong or weak acid?
strong
HBr is a strong or weak acid?
strong
HCl is a strong or weak acid?
strong
HClO4 is a strong or weak acid?
strong
HI is a strong or weak acid?
strong
HNO3 is a strong or weak acid?
strong
KOH is a strong or weak base?
strong
LiOH is a strong or weak base?
strong
NaOH is a strong or weak base?
strong
RbOH is a strong or weak base?
strong
0.1M NaOH + 0.1MNaOAc buffer or nah?
strong base and weak acid. so no
Why isn't Fe(OH)3 a strong base?
The Fe^3+ cation has a large positive charge concentrated on the single Fe atom, and thus the OH- anion will be more attracted to it. The OH anion will be less likely to hydrolyze the cation.
Why is H2S a weak acid?
Weak acids have a strong conjugate base.
0.01M HCl + 0.01M NaCl buffer or no?
no. strong acid and neutral salt
Why is F a weaker base than OH?
-F is the most electronegative atom and it is a small atom. The smaller and more electronegative an atom, the lower the energy of the electrons. -OH is a better base because
Indicators: what would be the pH when you're mixing a strong acid with a strong base? A)4-6 B)2-3 C)6-8 D)8-10
C
Which of these two is the weak acid and which is the strong acid? HClO4 vs HClO
-Stronger acid: HClO4. The ClO4 anion has a negative charge spread out over 4 O atoms. Therefore the anion will be less attractive to the proton, and the proton and anion will dissociate more easily in water. -Weaker acid: HClO. The ClO anion has a low negative charge concentrated on a single O atom, and thus will have a full negative charge. Thus, the proton will be more strongly attracted to the anion, and will not dissociate in water as easily. -all of these rules also apply to bases
Which of the following is NOT a strong base? A)Fe(OH)3 B)LiOH C)CsOH D)Ba(OH)2 E)RbOH
A
Which of the following acids, when reacted with an equivalent amount of KOH, will produce a pH closest to 7? Why? A)HSbF4 (pKa=-23) B)HCl (pKa=-20) C)C5H5N (pKa=3.5) D)NaOH (pKa=5) E)H2S)4 (pKa=-18)
A. -again, you are looking for the strongest acid, indicated by the biggest and most negative pKa value. When reacted with equal amounts of KOH, the HSbF4 will neutralize the strong base, thus we will only have the pH of water, 7. Remember: strong acids + strong bases neutralize each other
Indicators: What wold be the pH when you're mixing a weak acid with a strong base? A)5-7 B)8-10 C)9-12 D) 2-5
B
Which of the following acids matched with their pKa values will produce a pH closest to 7 for a 0.2M aqueous solution? Why? A)CH4 (pKa=22) B)HCl (pKa=-20) C)H2SO4 (pKa=28) D)HBr (pKa=-18)
B. -you are looking for the strongest acid, which is indicated by the biggest and most negative pKa value.
Which of the following will produce a pH=14 for a 1M aqueous solution? Why? A)HOCl (pKa=7.5) B)HClO (pKa=2) C)C2H6 (pka=30) D)H2S (pKa=-5)
C. -you're looking for the one with the highest positive pKa value. This indicates a molecule lacking acidic properties, which will not have an effect on the pH of the problem, thus the pH would be 0.
Indicators: What would be the pH when you're mixing a weak base with a strong acid? A)2-3 B)7-8 C)8-10 D)4-6
D
Which of the following salts will produce an acidic solution when dissolved in water? A)Ba(ClO4)2 B)CsI C)Rb2CO3 D)AlCl3 E)NaBr
D
Which of the following statements is false? A)weak acids have moderately strong conjugate bases B)Fe^3+ (aq) is considered a lewis acid C)HF is a weak acid in large part due to the concentrated negative charge on the small F- anion D)H2SO4 is a weak base E)compounds with nitrogen atoms having a lone pair of electrons are weak bases
E
Which of the following is the weakest base? A)F B)OH C)NH2 D)CH3
F
T/F. Cations can be basic, but only if there is a small positive charge spread out on a single atom.
F. Cations can NeVeR be BaSiC!!!!!!
T/F. Any organic compound containing nitrogen and and an additional proton will def form a basic solution.
F. anything with a N and an additional proton will make a weak acid
Which of the following is NOT a strong acid? A)HCl B)HNO3 C)HI D)H2SO4 E)H2S
H2S
What makes S^2- a strong conjugate base?
it has a large negative charge concentrated on a single atom, and thus it would be more attractive to a proton.
Weak acid + salt of a weak acid. Will this form a buffer?
yes
