Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Important redox reactions involving concentrated nitric acid Concentrated nitric acid is a powerful oxidizing agent. Please research the following chemical reactions so that you are able to establish the important patterns in these redox reactions. In each case justify the redox change by using oxidation numbers. What has been oxidized and what has been reduced 1. the decomposition of concentrated nitric acid 4HNO3 -------------2H20 + 4NO2 + O2 Show any change in oxidation number nitric acid has N ox number 5 this reduces to N ox number 4 in nitrogen dioxide 2. concentrated nitric acid with copper (with explanation) Cu + 4HNO3 ----------------Cu(NO3)2 + 2NO2 + 2H2O Cu moves from ox 0 to ox +2, N in nitric acid partly drops from +5 to +4 3. Moderately concentrated nitric acid with copper (with explanation) 3Cu + 8HNO3 --------------3Cu(NO3)2 + 4H2O + 2NO Some of the N moves from +5 to +2, copper moves from 0 to +2 4 Concentrated nitric acid with sulphur (with explanation) S + 6HNO3 ------------2H2O + 6NO2 + H2SO4 Here S jumps from 0 to +6, N from +5 to +4 5 Concentrated nitric acid with zinc (with explanation) Zn + 4HNO3 ----------Zn(NO3)2 + 2NO2 + 2H2O Zinc was 0 it becomes +2, some of the N moves from + 5 to +4 Redox Year 12. Reactions of concentrated nitric acid SOLUTIONS SHEET by HG 6 Concentrated nitric acid with carbon (with explanation) C +4HNO3 -------------2H2O + 4NO2 + CO2 Here C was 0 it becomes +4, Nin nitric acid is +5 it drops to +4 again Concentrated sulphuric acid can also act as an oxidizing agent. (It is not as powerful as nitric acid) Dilute sulphuric acid does not with copper metal. The concentrated acid does; Cu + 2H2SO4 --------CuSO4 + 2H2O + SO2 Here copper was 0 it becomes +2 (hence oxidized) Sulphur in the acid changes from +6 to +4 in sulphur dioxide Patterns When concentrated nitric acid undergoes redox change which gas is usually produced? Nitrogen Dioxide NO2 If concentrated sulphuric acid takes part in redox. Which gas is most likely? Sulphur Dioxide SO2 Redox Year 12. Reactions of concentrated nitric acid SOLUTIONS SHEET by HG