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Homework8 iversity of Pennsylvania - CHEM 100-Fall17-ASHE Activities and Due Dat

ID: 552973 • Letter: H

Question

Homework8 iversity of Pennsylvania - CHEM 100-Fall17-ASHE Activities and Due Dates Grade 11/2/2017 11:55 PM O 12.2/1410/31/2017 01:03 AM E Perodic Table Question 7 of 13 Map University Science Books peesanted by Sapling Lnaming General Chemistry 4th Edition Cryolite, NayAIFefs), an ore used in the production of aluminum, can be synthesized using aluminum oxide Balance the equation. Tip: if you need to clear your work and reset the equation click the button that looks ike two red arrows. O,s)+ NaOH+H Na, Air,+11,0 11.4 kilograms of AlgOsds).52.4 kilograms of NaOH(D and 52.4 kilograms of HF(g) react completely, how many kilograms of cryolite will be produced? Number Which reactants will be in excess? What is the total mass of the excess reactants left over after the reaction is complete? Number NaOH kg and Windows acer

Explanation / Answer

from balanced equation:

Al2O3 + 6NaOH + 12HF -----> 2Na3AlF6 + 9H2O

1 mol Al2O3 = 6 mol NaOH = 12 mol HF

no of mol of Al2O3 = W/MWT = 11.4*10^3/102 = 111.76 mol

no of mol of NaOH = 52.4*10^3/40 = 1310 mol

no of mol of HF = 52.4*10^3/20 = 2620 mol

limiting reactant = Al2O3

no of mol of Na3AlF6 formed = 2*111.76 = 223.52 mol

mass of Na3AlF6 formed = 223.52*210

    = 46.94 kg

excess reactants = NaOH , HF

mass of excess reagent = (1310- (111.76*6))*40 + (2620-(111.76*12))*20

             = 51.155 kg