Mass of plant food sample 10.500 g Mass of watch glass 5.000 g Mass of watch gla
ID: 477943 • Letter: M
Question
Mass of plant food sample 10.500 g Mass of watch glass 5.000 g Mass of watch glass and product 6.500 g Calculations 1. What is the mass of your precipitate MgNH4PO46H20)? 2. What is the molecular weight of MgNH4PO4 6H20? 3. How many moles of MgNH4PO4 6H20 are in your sample? 4. How many moles of P are in your sample of MgNH4PO46H20? Moles of P (moles, MgNHAPO4 6H20)(? mole P 1 mole MgNHAPO4 6H20) 5. How many grams of P are in your sample of MgNH4PO4 6H20? 6. How many grams of P are in your original fertilizer sample?Explanation / Answer
Mass of the precipitate = mass of product +watch glass - mass of watch glass
=6.5 g-5g = 1.5g
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Molar mass of MgNH4PO4.6H2O = 245.41 gm/mol
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moles of MgNH4PO4.6H2O = mass of MgNH4PO4.6H2O/ molar mass
= 1.5g/245.41g/mol = 6.11*10^-3 moles
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1 mole MgNH4PO4.6H2O contains 1 mole P. So total moles of P present in 6.11 *10^-3 moles product is as follows:
Moles of P = moles of MgNH4PO4.6H2O * 1 mole P/1mol MgNH4PO4.6H2O
= 6.11 *10^-3 moles * 1
= 6.11*10^-3 moles