A student heated 3.00 g3.00\text{ g}3.00 g of magnesium hydroxide to produce solid magnesium oxide and water vapour.
The reaction is: magnesium hydroxide→magnesium oxide+water vapour\text{magnesium hydroxide} \rightarrow \text{magnesium oxide} + \text{water vapour}magnesium hydroxide→magnesium oxide+water vapour
The student weighed the contents of the test tube after each minute of heating. The results are shown in the table below:
| Total heating time (minutes) | Mass of contents of test tube (grams) |
|---|---|
| 0 | 3.00 |
| 1 | 2.65 |
| 2 | 2.38 |
| 3 | 2.19 |
| 4 | 2.10 |
| 5 | 2.07 |
| 6 | 2.07 |
Find the minimum heating time needed for all of the magnesium hydroxide to be completely decomposed.
Calculate the total mass of water vapour produced by decomposing the magnesium hydroxide.