Question

1. Kevin had a small blue crystal of unknown composition and a large green anhydrous crystal of

known composition. He heated both crystals over a laboratory burner. The green crystal did not
give off steam nor did it change physical appearance. The blue crystal, when heated, gave off
water vapor and became a powder. What can you conclude about the blue crystal? Explain.

Answer 1

It can be concluded that the blue crystal is a hydrate. You can tell that it is a hydrate because when hydrates are heated, they give off water vapor proving that they had water chemically attached to their atoms.