acid and base equilibria questions...?

Question

okay these are multiple choice. Please answer any that you know for sure. if you are just guessing or can narrow any of the answers out please let me know...

1)Of the following, an aqeuous solution of ______will form basic solutions. (could possiblie be more than one of these)
a-NH4Cl
b-Cu(NO3)2
c-K2CO3
d-NaF

2) A 0.1M solution of ______has a pH of 7.00
A-Na2S
B-KF
C-NaNO3
D-NH4Cl
E-NaF

3) an aqueous solution of _____would be a basic solution.
A-NH4ClO4
B-KBr
C-NaCl
D-NaHSO4
E-Na2SO4

4)Of the following the acid of ______is the greatest.
a- CH3COOH
b-ClCH2COOH
c-Cl2CHCOOH
d-Cl3CCOOH
e- BrCH2COOH

5)a 0.1M solution of the sodium salt of which of the following anions will have the hightest pH.
A-IO2 -1
B-ClO2 -1
C-ClO -1
D-IO-1
E-IO3 -1

6)Which is a lewis base?
a Cl-
b BF3
c CN-
d H2O

7)hydrofluoric acid and____produce a buffur solution.
a HCl
b NaNO3
c NaF
d NaCl
e NaBr

Answer 1

1. c,d H2CO3 and HF are weak acids thus their salts with strong bases hydrolyze giving alkaline solutions. (or from another point of view the acids are weak and thus their conjugate bases (the anions of the salts) are strong enough to react with water producing alkaline solutions.

2.c. Only this is the salt of a strond base with a strong acid

3 e. The first dissocation of sulfuric acid is practically 100% but the second is not. That's why SO4(-2) will hydrolyze whereas HSO4(-) won't.

4.The more electronegative atoms near the -COOH group the stronger the acid. You don't specify what property you are comparing, so if you mean acid strength it is d which has 3 Cl atoms.

5. For XOn (-1) the bigger electronegativity of X and higher n (more O pull the e of the bond O-H better, facilitating the breaking of the bond and thus H+ production) the stronger the acid, thus the weaker the conjugate base and the lower the pH of the sodium salt. Thus the highest pH will be for the salt with the lowest n value and X with the smaller electronegativity. I has smaller electronegativity than Cl, thus the answer is d) IO-

6. A Lewis base can give an electron pair. All apart from b are Lewis bases, so it is a,c,d

7. HF is a weak acid, so you need it's conjugate base F-, thus the answer is c

Answer 2

i prefer to preface my answer via telling u that u can digital mail me with the different questions. it fairly is perplexing to respond to all 3 questions, yet ill attempt. a million. we see that H3O+ is the main effective acid, by using fact water is a very very vulnerable base. thye conjugate of a sturdy acid is a vulnerable base. the more desirable the acid, the weaker its conjugate. the more desirable the backside, the weaker its conjugate. 2. i understand for virtually particular that B(OH)3 is an ACID. frequently, all nonmetal OH's are acids. if u rearrange this formulation, u get H3BO3. i will declare D. 3. to discover the pH of a vulnerable acid, u take the sq. root of Ka x Molarity. on condition that all molarities are a million, take the sq. root of all the Ka's and take the destructive log of what u have been given. and the closest one to 7 is the winner. it fairly is the NH4+ i desire this facilitates.