Some solid calcium oxide in a test tube picks up water vapor from the surrounding to change completely into solid calcium hydroxide. An observed total initial weight (calcium oxide + test tube) f 10.860g goes eventually to 11.149g. What is the weight of the test tube?

To solve this problem, we need to find the weight of the test tube.

The weight increase of the reactants is due to the absorbed water vapor, which will react with calcium oxide to form calcium hydroxide.

First, let's calculate the weight of the calcium oxide used in the reaction:

Weight of calcium oxide = Final weight - Initial weight
Weight of calcium oxide = 11.149 g - 10.860 g
Weight of calcium oxide = 0.289 g

Since calcium oxide and calcium hydroxide have the same amount of calcium atoms, the weight of calcium hydroxide formed will be equal to the weight of calcium oxide used in the reaction.

Therefore, the weight of calcium hydroxide formed is 0.289 g.

Now, we need to determine the weight of the test tube.

Weight of the test tube = Total initial weight - Weight of calcium oxide
Weight of the test tube = 10.860 g - 0.289 g
Weight of the test tube = 10.571 g

Therefore, the weight of the test tube is 10.571 g.