# Molarity and Oxidation states

1. Oct 27, 2008

### 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

2. Oct 27, 2008

### Staff: Mentor

In what molar ratio do they react?

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

3. Oct 27, 2008

### 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.

4. Oct 27, 2008

100% OK now.