Question

You placed a sample of a hydrate of calcium chloride (CaCl2) in a weighed test tube, and weighed the filled test tube.

Then you heated it until no more water was evolved. After cooling, you weighed the test tube again.

Mass of empty tube (g) 13.5
Mass of filled tube before heating (g) 18.5
Mass after cooling (g) 16.2

Calculate the following:
1.Mass of hydrate originally taken

2.Mass of water evolved

3.Mass of anhydrous CaCl2 formed

4.Moles of anhydrous CaCl2

5.Moles of water evolved

6.Moles of water in the molecular formula of the hydrate

Answer 1

Answer:1.Mass of hydrate originally taken= 5.0g

2.Mass of water evolved=2.3g

3.Mass of anhydrous CaCl2 formed= 2.7g

4.Moles of anhydrous CaCl2= 0.024 moles

5.Moles of water evolved= 0.128 moles

Moles of water in the hydrated salt=5 moles

Step-by-step explanation:

The detailed solution is found in the images attached. The mass or the hydrate is obtained by subtracting the mass of the empty tube from the mass of the filled tube before heating as shown. All other detailed solutions are easily identified in the image attached.