Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

1) Identify the acid and the base in the following reactions. (Type your answer

ID: 892135 • Letter: 1

Question

1) Identify the acid and the base in the following reactions. (Type your answer using the format CO2 for CO2, (NH4)2CO3 for (NH4)2CO3, [NH4]+ for NH4+, and [Ni(CN)4]2- for Ni(CN)42-. Do not include state symbols in the answers.)

(a) O2-(aq) + H2O(l) 2 OH -(aq)

- acid

-base

(b) (CH3)3N(aq) + HCl(aq) (CH3)3NH+ (aq) + Cl -(aq)

-acid

-base

(c) CH3COOH(aq) + H2O(l) H3O+(aq) + CH3CO2-
- acid
  
-base

2) When each of the following pairs of aqueous solutions is mixed, does a precipitation reaction occur? If so, write the formula and name of the precipitate. (Type your answer using the format CO2 for CO2. Type NONE in the blanks if there is no precipitation reaction.)

(a) silver nitrate + sodium bromide
- formula

- name
  
(b) ammonium sulfate + iron(II) nitrate
-formula
  
-name

3) How many total moles of ions are released when each of the following samples dissolves completely in water?
(a) 0.296 mol of K2HPO4
- mol
(b) 5.80 g of MgSO47 H2O
- mol
(c) 6.641 1021 formula units of NiCl2
- mol

4) Select the classification for the following reaction.
Na3PO4(aq) + 3HCl(aq) 3NaCl(aq) + H3PO4(aq)

- combination
- none of these choices is correct   
- precipitation
- acid-base
- redox

Explanation / Answer

1a.

Acid H2O

Base O2-

1b

Acid HCl

Base (CH3)3N

1c

Acid CH3COOH

Base H2O

2a. AgBr     silver bromide

2b. NONE

3.a.     0.296x 3= 0.888                   2K+ and 1 HPO4- per formula unit

3b.   2 x 5.80 g of MgSO4.7H2O / 246.52 g/mol.= 0.0235 mol

( 1 Mg 2+ and 1 SO4- per formula unit)

3c. 6.641 x1021 unit/ 6.02 x 1023 (Avogadro constant) = 1.10 x10-2 mol

4. acid-base

   PO43-(aq) + 3H+(aq) = H3PO4(aq)     (net reaction)