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Is this the correct oxidation numbers for H and O in hydrogen peroxide H2O2; H 1+, O 1- . Why or why not ?

Explanation

Yes ,  H +1, O 1-  is the correct oxidation state of each element H and O in H2O2 because as per oxidation number rules the O oxygen in perooxides should be -1 and H is and +1 so these are correct oxidation numbers .

Answer

Yes H is +1 and O is -1 is peroxides so these oxidation numbers are correct .

What is the oxidation number of nitrogen in nitric acid,HNO3 ?

Explanation

The oxidation number of nitorgen in nitric acid HNO3 is

O = -2

H = + 1

above should be known to you since these are among oxidation number rules :

to find the oxidation number of N , we need to use the rule ' that the sum of the oxidation number of the each element of a compound is equal to the o if the compound is neutral or the net charge of it if the compound has a net charge.So, in HNO3 lets say that the Nitrogen charge is x

1 + X + (-2) 3 = 0

1+ x+ (-6) = 0

x -5 = 0

X = +5

Nitrogen has +5 oxidation number

Answer

Nitrogen has +5 oxidation number in HNO3

Is the reaction 2Al(s) + 3Cl 2 (g) ----> 2AlCl 3 (s) can be considered as the redox reaction ?

Explanation

In the reaction 2Al(s) + 3Cl2(g) -----------> 2AlCl 3 (s)

Al is changing its oxidation state from 0 to +3

Cl is changing its oxidation state from 3 to -1

so, Al is undergoing oxidation and Cl is undergoing reacdution .

Yes, it is oxidation reduction reaction .

Answer

Yes, since Al is underging an oxidation and Cl is undergoing reduction .

When 0.150 L of 0.10 M lead (II) nitrate and 0.100 L of 0.20 M sodium chloride are mixed? For PbCl 2 , K sp = 1.2 x10 - 5

Explanation

Precipitation reaction :

Pb(NO3)2(aq)+ 2NaCl(aq) ----------> PbCl2(s)+ 2NaNO3(aq)

Solubility reaction :

PbCl2(s) -----> Pb2+  +  2Cl-

Ksp is given and in order to find out if a precipitate form we need to find out Q

Q = [Pb2+][Cl-]2

1:1 mole ratios so initial [Pb2+] = [Pb(NO3)2] = 0.10 M;initial[Cl-] = [NaCl] = 0.20 M
after we combine the solution the total volume becomes .250 L , so the concentration of Pb2+ and Cl- ions is :
[Pb2+] =.10 M Pb2+ x .150 / .250 L = 0.060 M Pb2+
[Cl-] = 0.20 M Cl- x . 1 L / .250 l = 0.080 M Cl-
 
Q = (0.060)(0.080)2= 3.8 x 10-4
Q>Ksp, so PbCl2 does precipitate.Eq shifts to the left .
 
3.8
x10


 
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Answer
Q>Ksp, so PbCl2 does precipitate.Eq shifts to the left .
 
3.8
Topic

Mercury(I) chloride, Hg2Cl2.It has a Ksp equal to 1.3 × 10 − 18.What is the solubility of Hg2Cl2 ?

Explanation

The Solubility equilibrium is :

Hg2Cl2(s) <----->  Hg2 2+(aq) + 2Cl-(aq)
Solubility-product constant expression:
 
Ksp= [Hg22+][Cl-]2
now create an ICE equation :
 
        Hg2Cl2(s) <----->  Hg2 2+(aq) + 2Cl-(aq)
 I                                     0                      0
C                                  +x                      +x
E                                   -x                      -x
 
note that the concentration of Cl- ion would be twice the concentration of the Hg since the ratio of Hg2Cl2 is 1:2
Ksp = X.(2X)2
1.3  × 10 − 18 =x. 4x2
 
Ksp = 4X3
1.3 × 10-18 = 4x3
x3= 3.25 × 10-19
x= 6.88 × 10-7M
      
 
 
Answer

6.88 × 10-7M

Topic

0.133 mg of silver bromide AgBr will dissolve in 1.00 L of water. What is the value of Ksp for AgBr?

Explanation

The solubility equilibrium expression is :

AgBr (s) <-----> Ag+ (aq) + Br - (aq)

Solubility-product constant expression is :

Ksp= [Ag+][Br-]

The solubility is given as 0.133 mg/1.00 L, but Ksp uses molarity , so convert mg to g and then grams to moles by using the moalr mass  of the AgBr ( MM of AgBr is 187.72 )

0.133 mg/1.00 L x 1 mol / 187.72 = 7.083 x 10-7  M

So, as AgBr dissociates into 1 mol of each Ag+ and Br- ions the concentration of both ions would be 7.083 x 10-7  M.

Ksp= (7.083 × 10-7)2

Ksp= 5.02 × 10-13

 

 
Answer

Ksp= 5.02 × 10-13