University:
Texas State University
Course:
CHEM 1141 | General Chemistry Laboratory I
Academic year:

2024
Views:

340

Pages:

3
Author:

Riya J.

Copper Cycle Pre-Lab Assignment Purpose: The production of four different copper compounds through a series of reactions with metallic copper, Cu(s), and different reagents is conducted before ultimately being returned back to its original form that is metallic. Observations are recorded of all the chemical and physical changes in each reaction and the balanced chemical reaction for each reaction is written and classified. Lastly, the percent recovery of the final copper product is determined. Objectives: 1. Series of precipitation, acid-base, decomposition, and redox reactions on successive copper-based compounds are performed. 2. The percent recovery of all final copper products is calculated 3. 5 balanced chemical equations, and necessary sub-equations, are composed which is deduced from the classification of each reaction in the cycle Compounds: Cu wire Al wire 16 M HNO3 3 M NaOH 6 M H2SO4 6 M HCl ethanol deionized H2O Materials: 400 mL beaker 250 mL beaker 100 mL beaker Glass stirring rod 50 mL graduated cylinder 10 mL graduated cylinder porcelain evaporating dish hot plate/stir plate Chemical Hazards: - Corrosive chemicals that can burn flesh and can serious burns (HNO3, HCl, H2SO4) - NO2 produces toxic brown gas that can cause health problems if inhaled or ingested - Ethanol is flammable Physical Hazards: - Broken glassware can cause cuts - Hot glassware can cause burns Balanced Equation: 1) 2) 3) 4) 5) Precipitation reaction: Cu(NO3)2 (aq) + 2 NaOH (aq) -> Cu(OH)2(s) + 2 NaNO3(aq) Redox reaction: Cu(s) + 4HNO3 (aq) -> Cu(NO3)2 (aq) + 2 NO2 + 2H2O(l) Redox reaction: CuSO4(aq) + 2Al (s) -> 3Cu(s) + Al2(SO4)3 Acid + Base Reaction: CuO(s) + H2SO4 (aq) ->CuSO4(aq) + H2O(l) Decomposition reaction: Cu(OH)2(s) ->CuO(s) + H2O(l) Outline: REACTION 1: Formation of Cu(NO3)2 - Record mass of pre cut Cu(s) wire Add 16 M HNO3 to beaker Add DI water REACTION 2 : Formation of Cu(OH)2 - Add 3M NaOH to beaker REACTION 3: Formation of CuO - Heat solution of reaction 2 - Remove from heat and once solid is settled throw our colorless solution - Add water and heat - Wash solid with remaining water REACTION 4: Formation of CuSO4 - Add 6 M H2SO4 with isolated CuO REACTION 5: Formation of Cu(s) - Place Al(s) with CuSO4 and add 5 drops of 6 M HCl Place beaker on hotplate and stir Prepare steam bath Transfer Cu to evaporating dish Wash Cu(s) with DI water Wash Cu(s) with ethanol - Put evaporating dish on top of steam bath Remove Cu(s) from evaporating dish when dried Record mass