Some solid Calcium Oxide in a test tube picks up water vapor from the surroundings to change completely to Calcium Hydroxide. An observed total initial weight of 10.860 g goes eventually to 11.149 g. What is the weight of the test tube?
To find the weight of the test tube, we need to subtract the weight of the resulting Calcium Hydroxide from the observed total weight.
The weight change from Calcium Oxide to Calcium Hydroxide is:
11.149 g - 10.860 g = 0.289 g
Since the Calcium Hydroxide was formed by the combination of Calcium Oxide and water vapor, the weight change is solely due to the water vapor. Therefore, the weight of the water vapor is 0.289 g.
Since the water vapor came from the surroundings, the weight of the test tube is the difference between the observed total weight and the weight of the water vapor:
10.860 g - 0.289 g = 10.571 g
Hence, the weight of the test tube is 10.571 g.