Answer:
Stage 1: 1 days.
Stage 2: 2-3 days.
Stage 3: 4-5 days.
Stage 4: 6 days.
Stage 5 (a-c): 7-12 days.
Stage 6: c. 17 days.
Stage 7: c. 19 days.
Stage 8: c. 23 days.
Answer:
The precipitate is CuS.
Sulfide will precipitate at [S2-]= 3.61*10^-35 M
Explanation:
<u>Step 1: </u>Data given
The solution contains 0.036 M Cu2+ and 0.044 M Fe2+
Ksp (CuS) = 1.3 × 10-36
Ksp (FeS) = 6.3 × 10-18
Step 2: Calculate precipitate
CuS → Cu^2+ + S^2- Ksp= 1.3*10^-36
FeS → Fe^2+ + S^2- Ksp= 6.3*10^-18
Calculate the minimum of amount needed to form precipitates:
Q=Ksp
<u>For copper</u> we have: Ksp=[Cu2+]*[S2-]
Ksp (CuS) = 1.3*10^-36 = 0.036M *[S2-]
[S2-]= 3.61*10^-35 M
<u>For Iron</u> we have: Ksp=[Fe2+]*[S2-]
Ksp(FeS) = 6.3*10^-18 = 0.044M*[S2-]
[S2-]= 1.43*10^-16 M
CuS will form precipitates before FeS., because only 3.61*10^-35 M Sulfur Ions are needed for CuS. For FeS we need 1.43*10^-16 M Sulfur Ions which is much larger.
The precipitate is CuS.
Sulfide will precipitate at [S2-]= 3.61*10^-35 M
This is the same as its freezing point
hope this helps
Balancing redox reactions:
Oxygen should be balanced by adding 
as needed, while hydrogen should be balanced by adding 
.
What is a redox reaction?
Redox reactions, also known as oxidation-reduction reactions, involve the simultaneous oxidation and reduction of two different reactants.
The Half-Equation Method is one technique used to balance redox processes. The equation is divided into two half-equations using this technique: one for oxidation and one for reduction.
By changing the coefficients and adding , , and 
in that order, each reaction is brought into equilibrium:
- By putting the right number of water () molecules on the other side of the equation, the oxygen atoms are brought into balance.
- By adding ions to the opposing side of the equation, one can balance the hydrogen atoms (including those added in step 2 to balance the oxygen atom).
- Total the fees for each side. Add enough electrons () to the more positive side to make them equal. (As a general rule, and are nearly always on the same side.)
- The on either side must be made equal; if not, they must be multiplied by the lowest common multiple (LCM) in order to make them equal.
- One balanced equation is created by adding the two half-equations and canceling out the electrons. Additionally, common terms should be eliminated.
- Now that the equation has been verified, it can be balanced.
Learn more about redox reaction here,
brainly.com/question/20068208
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