What Does a Muddy Precipitate Indicate in a Redox Reaction?

In summary, the experiment suggests that the gas being bubbled into the orange solution of substance 'A' is a reducing agent, potentially NH3, SO2, NO2, H2S, or Cl2. To test the validity of this inference, further experiments can be conducted using these gases and observing their effects on the solution. Additionally, the green color of the solution after being warmed with conc HCl indicates that the soln is either (Cr2O7)2- or Fe3+, both of which are reduced to a green soln. Further experiments can be carried out to determine the exact gas and soln involved in this reaction.
  • #1
AikiGirl
4
0

Homework Statement


"State what you would infer from each of the following observations and suggest experiments you would carry out to test the validity of your inferences: When an unpleasant smelling gas was bubbled into an orange solution of a substance 'A', a solid was formed and the mixture appeared muddy in colour. On warming with conc HCl, some of the solid dissolved and the solution appeared green in colour."


Homework Equations


This is what I came up with:
Possible gases: NH3, SO2, NO2, H2S, Cl2
Possible solns: Br2, (Cr2O7)2-, Fe3+


The Attempt at a Solution



The soln is either (Cr2O7)2- or Fe3+ because they both are reduced to a green soln.

So the gas should be oxidised.

NH3: (NH4)- (same oxidation state)
SO2: (SO3)2- (same oxidation state), (SO4)2- (no ppt),
NO2: (NO3)- (same oxidation state),
H2S: S (yellow ppt), SO2 (gas), (SO3)2-, (SO4)2- (no ppt),
Cl2: Cl- (mostly soluble)

That's what I can figure out, not sure if it's correct, and not sure where to go from here. Any help would be appreciated.
 
Physics news on Phys.org
  • #2
AikiGirl said:
The soln is either (Cr2O7)2- or Fe3+ because they both are reduced to a green soln.

So the gas is a reducing one.

Note: gas can reduce the substance in solution, but the precipitate doesn't have to contain reduced form of the gas - it can as well contain gas in the form introduced (protonated/neutralized depending on circumstances).
 

Related to What Does a Muddy Precipitate Indicate in a Redox Reaction?

What is a redox reaction?

A redox reaction is a chemical reaction in which there is a transfer of electrons between two species. One species loses electrons and is oxidized, while the other species gains electrons and is reduced. This transfer of electrons is what gives the reaction its name, as "redox" is short for reduction-oxidation.

What are the main types of redox reactions?

The main types of redox reactions are synthesis, decomposition, single replacement, and double replacement. In a synthesis reaction, two or more substances combine to form a single product. In a decomposition reaction, a single compound breaks down into two or more simpler substances. In a single replacement reaction, an element replaces another element in a compound. In a double replacement reaction, two compounds switch partners to form two new compounds.

How are redox reactions balanced?

Redox reactions are balanced by making sure that the number of electrons lost by the oxidized species is equal to the number of electrons gained by the reduced species. This can be done by adding coefficients to the reactants and products, as well as balancing the charges on each side of the reaction.

What is an oxidizing agent?

An oxidizing agent is a substance that causes another substance to lose electrons and become oxidized. In other words, it is a substance that is reduced in a redox reaction. Common oxidizing agents include oxygen, hydrogen peroxide, and chlorine.

What is a reducing agent?

A reducing agent is a substance that causes another substance to gain electrons and become reduced. In other words, it is a substance that is oxidized in a redox reaction. Common reducing agents include metals, hydrogen gas, and carbon monoxide.

Similar threads

What Determines Oxidizing and Reducing Agents in Redox Reactions?
    • Biology and Chemistry Homework Help
Replies
1
Views
7K
What Are the Key Concepts in Understanding Redox Reactions and Phases of Matter?
    • Biology and Chemistry Homework Help
Replies
2
Views
4K

Hot Threads

Recent Insights

Back
Top