Question

16 Question (1 point) The reaction of Cr2O3 with silicon metal at high temperatures will make chromium metal. 2Cr,0g(s)+3Si(s) 4Cr()+3Sio, (s) The reaction is begun with 179.00 g of Si and 89.00 g of Cr2O3 7th attempt

Answer 1

The gwen scostienis 2.Connests) + 3 si (s) → ucele) + 3 sieztsy In the balanced chemical equation 2 moles of craz react with 3 moles of si to give the products First we need to calculate the number of moles from given masses of reactants.

The formula to calculate number of moles is : U Number of Moles - Mass 70 Molar Mass - Given mass of Co= 89.00g si = 179.00g Also, Molar mass of si= 28.08 g/mol Molar Mass of Calg = 151.99 g/mol - using we get Number of Moles of Si- 179.00 g _28.08 g mol = 6.325 moles Number of moles of Gozes 89:204 - 151.99 g/mol -=0.586 moles _ _ - According to the balanced Chemical Equation, 2 moles of C react with Sis 3 moles mole of Cro will react with Si= 3 moles 2 P =1.5 moles So 0.586 moles of craz will react with si - (1.5 x 0.586) moles = 0.819 moles

Thus, moles of si required to completely with 89.00 g for of ce are 0.879 moles But number of moles present react 0.586 moles) بجمعهو لموقعكده ده which means ومععلاعمار in agent present in excess. is Silicon (si). 6.305 smoles of Sirenly 0:879 moles will be consumed. Mass of si in 0.879 moles = (No of moles) & (rolar of ses - (By using ) = (0.879 mot) x (28.08 g/mol) = 24.68 g This out of 179.00 g of si, only 24.68 g of it will get consumed in the reaction So Excess si left after the reacties is complete (790.00-24.6854 (154.32g