One of the steps involved in isolating uranium
from its ore is reacting the ore with fluorine
to form uranium hexafluoride (UF6) in the
reaction
U + F6 → UF6 .
If 2 g of UF6 are recovered from 22 kg of
ore, what is the weight % of uranium in the
ore?
Answer in units of %.
Same process as Ag2CrO4 and MgCO3 problems. Post your work if you get stuck.
To find the weight percent of uranium in the ore, we need to determine the amount of uranium present in the 22 kg of ore and then calculate the percentage based on the total weight.
Step 1: Convert the weight of UF6 recovered from the ore to the weight of uranium.
The molecular weight of UF6 is calculated as:
U: 238.03 g/mol
F6: (19.00 g/mol) x 6 = 114.00 g/mol
UF6: 238.03 g/mol + 114.00 g/mol = 352.03 g/mol
Thus, 1 mole of UF6 weighs 352.03 g and contains 1 mole of uranium.
Using the given weight of 2 g of UF6 recovered, we can calculate the moles of UF6:
2 g / 352.03 g/mol = 0.00568 mol UF6
Therefore, the moles of uranium in the ore are also 0.00568 mol.
Step 2: Calculate the weight percent of uranium in the ore.
The weight percent is calculated as:
% weight of uranium = (weight of uranium / weight of ore) x 100
The weight of uranium is the molar mass (238.03 g/mol) multiplied by the number of moles (0.00568 mol):
weight of uranium = 238.03 g/mol × 0.00568 mol = 1.354 g
The percentage is then calculated using the given weight of the ore (22 kg):
% weight of uranium = (1.354 g / 22,000 g) x 100 = 0.00616%
Therefore, the weight percent of uranium in the ore is approximately 0.00616%.