Chromium metal can be produced from the high temperature reaction of Cr2O3 with
ID: 1030693 • Letter: C
Question
Chromium metal can be produced from the high temperature reaction of Cr2O3 with silicon or aluminum by each of the following reactions: Cr2O3+2Al—> 2Cr + Al2O3 2Cr2O3+ 3Si—> 4Cr + 3SiO2 Calculate the number of grams of aluminum required to prepare 337.0g of chromium metal by the first reaction. Calculate the number of grams of silicon requires to prepare 337.0 g of chromium metal by the second reaction.Chromium metal can be produced from the high temperature reaction of Cr2O3 with silicon or aluminum by each of the following reactions: Cr2O3+2Al—> 2Cr + Al2O3 2Cr2O3+ 3Si—> 4Cr + 3SiO2 Calculate the number of grams of aluminum required to prepare 337.0g of chromium metal by the first reaction. Calculate the number of grams of silicon requires to prepare 337.0 g of chromium metal by the second reaction.
Cr2O3+2Al—> 2Cr + Al2O3 2Cr2O3+ 3Si—> 4Cr + 3SiO2 Calculate the number of grams of aluminum required to prepare 337.0g of chromium metal by the first reaction. Calculate the number of grams of silicon requires to prepare 337.0 g of chromium metal by the second reaction.
Explanation / Answer
1.
Moles of Cr = mass of Cr / molar mass of Cr = 337.0 / 52 = 6.48 mol
From the balanced equation,
2 mol of Cr is formed from 2 mol Al
SO, moles of Al required to prepare 337.0 g. of Cr = 6.48 mol
Mass ofAl required = moles * molar mass = 6.48 * 27.0 = 175. g.
2.
From the balanced equation,
4 mol of Cr is formed from 3 mol of Si
Then, 6.48 mol of Cr is fromed from 6.48 * 3 / 4 = 4.86 mol of Si
Mass of Si required = moles * molar mass = 4.86 * 28.1 = 136.6 g.