When Sulphur dioxide gas is passed through saturated solution of hydrogen sulphide, reaction takes place .
(a)Write a chemical reaction.
(b)Name the reducing and oxidising agent.
(c)Name the substance getting oxidised and reduced.
Answers
Answer:
Hydrogen sulphide is a reducing agent.
Explanation:
A good starting point for any reaction is to look at oxidation numbers. If they change, a redox reaction has occurred.
Here are some thoughts.
A dehydrating agent will extract water from another reactant. I would say that you need a hydroxyl (OH) group for this to occur. A dehydrating agent could be an acid and protonate the OH group, which can then leave as water. A catalyst is not used up in the reaction, so is hydrogen sulphide used up?
Hydrogen is usually in a +1 oxidation state and oxygen a -2 state.
Reactants
H+12S−2
S+4O−22
Products
S0
H+12O−2
Look at H2S, the oxidation number of sulphur has gone from -2 to 0. This means that it has been oxidised and is therefore a reducing agent.
For SO2, the oxidation number of sulphur has gone from +4 to 0. This is a reduction and makes SO2 an oxidising agent. We can essentially ignore H and O in this case as they don't change.