The thermo gravimetric trace below shows mass loss by Y2(OH)5Cl xH2O upon heating. In the first

The thermo gravimetric trace below shows mass loss by Y2(OH)5Cl ˆ™ xH2O upon heating. In the first step, waters of hydration are lost to give 8.1% mass loss. After a second decomposition step, 19.2% of the original mass is lost. Finally, the composition stabilizes at Y2O3 above 800°C.
(a) Find x in the formula Y2(OH)5Cl ˆ™ xH2O. Because the 8.1% mass loss is not accurately defined in the experiment, use the 31.8% total mass loss for your calculation.
(b) Suggest a formula for the material remaining at the 19.2% plateau. Be sure that the charges of all ions in your formula sum to 0. The cation is Y3+.

Transcribed Image Text:

← 31.8% Y203 30F FM 225.81 25 19.2% 10 FM 298.30-8.1% FM 298.30+x (18.015) 200 400 600 1000 1 500 Temperature (C)