Question

I need help with the following questions 1,2,3 the molarity for Sodium Carbonate is .50 and for Calcium Nitrite is .25 the volume for both is 100mL

Lab 7 Post-Lab Upload Write out the molecular, ionic, and net ionic equations for the precipitation reaction (you should already have these in your notebooks from lab. Make sure the molecular equation is properly balanced, we will use it for the below calculations. Molecular: Naz CO3(aq) + Ca(NO3)2(aq) - 2 NaNO3)(aq) + CaCO3 (5) Ionic: 2 Natrags + collag) + (a?"luq) + 2NO3 lug - CaCO3(s) + 2 Nat+2 No₃ Net lonic. ca tag) + CO -> CaCO315) Report the Molarities of the two solutions prepared in lab, and the volumes of each solution that you reacted together. 1) Use the above initial molarities and volumes to perform a limiting reactant calculation for this reaction. Make sure to identify which solution acted as the limiting reactant. 2) Use the limiting reactant to calculate the theoretical yield of the reaction. 3) Use the actual yield to calculate the percent yield of the reaction. Explain your percent yield. If it is above 100%, explain what could have caused that result. If it is below 100%, give reasons for why it might be low.

Answer 1

For identification of limiting reagent we need to find the number of moles of each reagent and the one which has less moles will be the limiting reagent.

Na2CO3 (aq) + Ca(NO3)₂ (aq) → 2NG(NO3) ag + CaCO₃ (s) Given, NaCO3 = 0.5 m & volume = lsomt Ca(NO3) = 0.25M. -0.1L To find out limiting reagent we need to know the number of moles of both reagent. Moles - Volume x concentration. Moles of Naco, = 0.58 0.12 = 0.05 moles Moles of Ca(NO3)2 = 0.25 mx 6) = 0.025 moles As Ca(NO3), is in less amont, it get consunted totally and hence ca(NO3)2 is the limiting reagent. to calculate theontical yield we will use ca CNO3)2, as it is limiting reagent. As in Equation, I mol of Ca(NO3) produces 1 mol of Calozi Hence 0.025 moles of Ca(NO₃) produces 0.025 moles of caloze Theoretical yield = weight of 0.025 moles Laco, = 0.025% molar mass of Caloz = 0.025% 100 g/mol = 2.5g

() As actual yield is not provided . Pescentage Yield can't be obtained. sell | Percentage yield = actual yield Bull Percentage yiero Theoretical yield etical yieutivo Explaination to pescout yield less than 100 %. ast can occur because there is always human error associated with it. ► Also instrumentation error, where exact Value cant be measused. → Evaporation occurs in liquids which then affect the yiel. a while transtessing liquids also there still - remains some in the container side wallts. — Also may be the reactants does not realt with 100% efficieny. If pescentage yield is more than 100 %. - It might occur that curral yield is more than theoritical yield because sometimes produits absorb moisture and increase the weight. Formation of impurities can also lead to more aniont of actual product and % yield will be more than loo.