Phosphorus is obtained primarily from ores containing calcium phosphate. If a particular ore contains 57.8% calcium phosphate, what minimum mass of the ore must be processed to obtain 1.00 kg of phosphorus?

Video transcript

Welcome back everyone in this example, we're told that zinc is extracted from an ore containing 68.4% zinc sulfide. And we need to determine the mass of the ore that is required to obtain g of zinc. So because we're given a percent by mass, we have according to the prompt 68.4% of zinc sulfide. To recall that zinc sulfide is represented as Z. N. S. And this percentage, we can determine or assume we have 100 g of ore that gives us our 68.4 g of zinc sulfide. So we would assume that we have 100 g of four. So we're going to take the 68.4 g of our zinc sulfide from our ore. And because we want our final unit to be mass of zinc, we want to go ahead and place our molar mass of zinc and grams in the denominator. Or sorry, our molar mass of zinc sulfide by the gram unit in the denominator. And so from our periodic table, we would see that we have a molar mass of 97.47 g of zinc sulfide for one mole of zinc sulfide. And so this allows us to get rid of grams of zinc sulfide and now we want to go ahead and get into grams of zinc as our final unit. But because we are at moles of zinc sulfide, we want to use a multiple ratio where we see that for one mole of zinc sulfide. Seeing how many atoms, I think we have, we have just one atom. So that would be equivalent to one mole of zinc in one mole of zinc sulfide. And so now we can cancel out our moles of zinc sulfide. And we're left with moles of zinc where we can finally get into grams of zinc by recalling from the periodic table the molar mass of zinc where we see that for one mole of zinc, we have an equivalence of 65.38 g of zinc. And so now we can cancel out moles of zinc. We're left with grams of zinc and in our calculators, we should get a value of 45.88 g of zinc. And so we would say that therefore 100 g of our ore produces 45.88 g of zinc. But because the prompt asks how much The mass of your that is required to obtain 750 g of zinc would be, we need to figure that out. And so we're going to use the calculation that we just found as a conversion factor. And so because the prompt wants to know what we would produce from 750g of zinc, we're going to want to cancel out grams of zinc by using what we just calculated in the denominator. So we would say 45.88 g of zinc and will actually plug that in as blue. So it's clear. So 45.88 g of zinc is produced from 100 g of our or And so now we can finally get rid of our units grams of zinc leaving us with our massive ore required to make 750g. And so this is going to give us a mass equal to a value Of 1634 g of your. And because our core is the larger quantity here, because we have 100 g of it. We're going to convert this to a larger unit being in kilograms as mass. So we can recall that to go from grams to kilograms are prefix kilo tells us that for one g we have 10 to the negative third power kilograms. So this allows us to cancel out our smaller unit grams leaving us with the larger unit kilograms and we have a final mass of our or required being 1.63 kg of our your required To make our 750 g of zinc. And so our final answer is going to be our 1.63 kg of or that is required and this would correspond to choice a and our multiple choice. So a is our final answer. I hope that everything that I reviewed was clear. If you have any questions, please leave them down below and I will see everyone in the next practice video