Thanks for any help! Q: In the reaction:Cu+ 4HNO3 > Cu(NO3)2 + 2NO2 +2H2O, 1.36
ID: 687199 • Letter: T
Question
Thanks for any help! Q: In the reaction:Cu+ 4HNO3 > Cu(NO3)2 + 2NO2 +2H2O, 1.36 grams of Cu metalwas reacted with 10.0ml of 9M nitricacid a. Calculate moles of each reactant I got ..0225 mole of solute for HN03 withmolarity equation and .021 moles for Cu. B. Which reactant is limiting I choseCu (less moles) Here is where I get stuck C. The CU(NO3)2 was heated toboiling to drive off water. Resulting solid behind was driedand weighed . The yield of precipitate (MM=187.56) wasproduced at 4.15g What was % yield? My theoretical yield comesout lower than 4.15g (3.93g) which seemswrong. I took Limiting reactants moles .021 and multiplied by MM ofCu(NO3)2. Thanks for any help! Q: In the reaction:Cu+ 4HNO3 > Cu(NO3)2 + 2NO2 +2H2O, 1.36 grams of Cu metalwas reacted with 10.0ml of 9M nitricacid a. Calculate moles of each reactant I got ..0225 mole of solute for HN03 withmolarity equation and .021 moles for Cu. B. Which reactant is limiting I choseCu (less moles) Here is where I get stuck C. The CU(NO3)2 was heated toboiling to drive off water. Resulting solid behind was driedand weighed . The yield of precipitate (MM=187.56) wasproduced at 4.15g What was % yield? My theoretical yield comesout lower than 4.15g (3.93g) which seemswrong. I took Limiting reactants moles .021 and multiplied by MM ofCu(NO3)2. I took Limiting reactants moles .021 and multiplied by MM ofCu(NO3)2.Explanation / Answer
The limiting reactant is not Cu. Yes there are more moles of HNO3, but you need 4 times as many moles of the HNO3 as Cu for the reaction to proceed. This is from the reaction stoichiometry. Recalculate with HNO3 as the limiting reactant.