Question

The uranium used for nuclear fuel exists in nature in several minerals. Calculate how many moles of uranium are in 8.00 moles of the following:
1. carnotite, K2(UO2)2(VO4)2 • 3H2O
2. uranophane, CaU2Si2O11 • 7H2O
3. autunite, Ca(UO2)2(PO4)2 • 10H2O

Answer 1

For calculating the number of moles of uranium, we can count how many atoms of uranium exist in 1 molecule of the given, and multiply this by the given 8.00 moles.
Carnotite contains (UO2)2, meaning that it has 2 U atoms. Multiplying by 8 gives 16 moles of uranium.
Uranophane contains U2, meaning it has 2 U atoms. Multiplying by 8 gives 16 moles of uranium.
Autunite contains (UO2)2, meaning it has 2 U atoms. Multiplying by 8 also gives 16 moles of uranium.
Therefore, in 8 moles of all 3 compounds given, there are 16 moles of uranium.