Question

A student was determining the formula for the hydrate of barium chloride, $Ba{Cl}_2$ in a laboratory. The student cleaned, dried, and determined the mass of the crucible and cover and then added a sample of the hydrate to the crucible and determined the mas after that the sample was heated in crucible strongly for 10 minutes. The sample in the crucible and cover was cooled and the mass was determined. The mass data is provided in the table below:
Mass of crucible and cover is 31.623 grams.
Mass of crucible, cover and sample prior to heating is 33.632 grams.
Mass of crucible, cover, and sample after heating is 33.376 grams.
Which of the following would be the best next step in the procedure?

• A. Add additional $Ba{Cl}_2$ hydrate to the crucible.
• B. Add distilled water to the crucible.
• C. Heat the crucible and contents for an additional 10 minutes and measure the mass again.
• D. Determine the melting point of the product.
• E. No additional steps are necessary.

Answer 1

Answer: (C)

Heat the crucible and contents for an additional 10 minutes and measure the mass again.

The following would be the best next step in the procedure.
Heat the crucible and contents for an additional 10 minutes and measure the mass again. This will ensure that there is no further loss in mass. It means complete removal of water.