Concentrated sulfuric acid is an oxidizing acid which can oxidize carbon to carbon dioxide while sulfuric acid is reduced to sulfur dioxide. This is a redox reaction because oxidation numbers of carbon and sulfur atoms are changed. We will discuss about characteristics of carbon and sulfuric acid reaction in this tutorial.
Hot, concentrated sulfuric acid should be used to oxidize carbon to carbon dioxide. During that time, sulfur atom in sulfuric acid is reduced to sulfur dioxide. Therefore, this is a redox reation.
Because, this reaction is a redox reaction, we can follow theories of balancing redox chemical equations. Below, each step of balancing is explained in detail.
We have already learned, carbon is oxidized and and sulfur atom in sulfuric acid is reduced.
Oxidation number difference for carbon and sulfur is 4 and 2 respectively. Therefore ratio is 4:2. You can simplify this ratio as 2:1. Nw, exchange differences.
C + 2H2SO4 → CO2 + 2SO2 + H2O
Now, oxidizing and reducing atoms are balanced. Lets balance rest of atoms by observing left and right side of reaction.
C + 2H2SO4 → CO2 + 2SO2 + 2H2O
Questions asked by students
From both names and chemical formula, define a same compound. Sulfuric acid is used in americaal english and sulphuric acid is used in british english.
Two gases are produced when sulphuric acid reacts with carbon. They are sulphur dioxide and carbon dioxide. Both are acidic gases and sulfur dioxide is slightly acidic than carbon dioxide.
Dilute sulphuric acid does not show characteristics of oxidizing acid. Therefore, dilute sulphuric acid does not react with carbon. Only hot concentrated sulphuric acid show characteristics of being a oxidizing acid.
Carbon is at solid state and sulfuric acid exists as a aqueous solution. From the products, Sulphur dioxide and carbon dioxide are in the gaseous state. Water is at liquid state.