Observing Reactions of Sulfuric Acid free essay sample

Assessment task 3 oral presentation summary Description of the experiment * Aim:To observe the reactions of sulfuric acid as an oxidising agent and as a dehydrating agent. Equipment: * 20mL of concentrated sulfuric acid * 20mL of 2mol/L sulfuric acid * 2 small pieces of each of copper, zinc and iron * Sandpaper * 10 test tubes * Test tube rack * 2g of sugar crystals (sucrose) * 2 wooden ice-cream sticks * 10mL measuring cylinders Steps: A: Sulfuric acid as an oxidising agent 1. Clean pieces of metal with sandpaper to remove oxide coating. . Add a piece of each metal to a separate test tube. 3. Add 5mL of concentrated sulfuric acid to each test tube. 4. Record the observations. 5. Repeat the experiment with 2mol/L sulfuric acid. B: Sulfuric acid as dehydrating agent 1. Place 1g of sugar (sucrose) and a wooden ice-cream stick into separate test tube. 2. Add 1-2mL of concentrated sulfuric acid to each test tube. 3. Record the observations. 4. Repeat the experiment with 2mol/L sulfuric a cid Risk assessment * Conc. We will write a custom essay sample on Observing Reactions of Sulfuric Acid or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page sulfuric acid is highly corrosive * If conc. Sulfuric acid is spilt, do not add water * Hydrogen sulfide gas Results | Observations| | Conc. Sulfuric acid| 2 mol/L sulfuric acid| Copper| No observable change| No observable change| Zinc| No observable change| No observable change| Iron| * Exothermic reaction * Bubbling gas| No observable change| Sugar| * Exothermic reaction * Black solid is produced and pushed out from the test tube * Gas with rotten egg smell is released| No observable change| Wood| * Black layer is formed on the wood| No observable change| Validity and reliability Experiment was not repeated * Low reliability * Results not consistent with the known theory * Invalid * Require to eliminate experimental errors Analysis of the results HSC syllabus dot-points: * Students learn to: Describe, using examples, the reactions of sulfuric acid acting as: * an oxidising agent * a dehydrating agent * Students: * Perform first-hand investigations to observe the reactions of sulfuric acid acting as: * an oxidising agent * a d ehydrating agent Conc. sulfuric acid: Reaction with metal – as an oxidising agent: Fes+2H2SO4lFeSO4(aq)+SO2(g)+2H2O(l) * Bubbling gas * FesFe2+(aq)+2e- * 2H+(aq)+2HSO4-(aq)+2e-SO2g+2H2O(l)+SO42-(aq) * Hydrogen sulfate ion act as oxidising agent * Some metals such as zinc did not react * Oxide layer * Heat * Leave overnight 2mol/L sulfuric acid: * Zns+H2SO4aqZnSO4aq+H2g * Zns+2H+aqZn2+aq+H2(g) * Oxidant is hydrogen ion Conc. sulfuric acid: Reaction with sugar and wood – as a dehydrating agent: * C12H22O11sH2SO4Â  12Cs+11H20(l) * Hydrogen sulfide gas 2mol/L sulfuric acid: * Sugar and wood do not react with dilute sulfuric acid