Molarity and Oxidation states

Quincy

1. The problem statement, all variables and given/known data

I wasn't sure about some of these problems, am I doing them correctly?

1) What volume of each of the following bases will react completely with 25.00 mL of 0.200 M of HCl?

a) 0.100 M NaOH

.02500 L x .200 mol HCl/1 L = .00500 mol HCl

.100 M NaOH = .00500 mol NaOH/v ~ v = .0500 L NaOH

b) 0.0500 M Ba(OH)₂

.0500 M Ba(OH)₂ = .00500 mol HCl/v ~ v = .100 L Ba(OH)₂

c) .250 M KOH = .00500 mol KOH/v ~ v = .0200 L KOH

2) Assign oxidation states for all atoms in each of the following compounds:

a) KMnO₄
K: -1
O: -2
Mn: +7

b) Hg₂Cl₂
Hg: +1
Cl: -1

c) NaBiO₃
Na: +1
Bi: +5
O: -2

d) CO
C: +2
O: -2

e) Ca(NO₃)₂
Ca: +2
N: +5
O: -2

f) HAsO₂
H: +1
As: +3
O: -2

3) Specify which of the following are redox reactions, and identify the oxidizing agent, the reducing agent, the substance being oxidized, and the substance being reduced.

a) HCl (g) + NH₃ (g) --> NH₄Cl (s)

-- not a redox reaction

b) Cu (s) + 2Ag⁺ (aq) --> 2Ag (s) + Cu²⁺ (aq)

Oxidized: Cu

oxidizing agent: Ag⁺

Reduced: Ag⁺

Reducing agent: Cu

Borek

In what molar ratio do they react?

Alkali metals in compounds have always the same ON, and it is not -1.

Quincy

2HCl + Ba(OH)₂ --> BaCl₂ + 2H₂O

HCl and Ba(OH)₂ react in a 2:1 ratio, I realized that after I posted the thread; so the volume of Ba(OH)₂ is 0.0500 L?



That was a typo, I meant to say K: +1.

Borek

100% OK now.