Answer
3 grams
1.3 grams
Rate Decreases
Work Step by Step
In the first 30 minutes, the mass of sucrose decomposes from 10 grams to 7 grams.
Thus 3 grams of sucrose decompose in the first 30 minutes.
At 90 minutes, there is 2.5 grams of sucrose left.
At 120 minutes, there is about 1.2 grams of sucrose left.
2.5 g - 1.2 g = 1.3 g
Thus in the 30 minute interval between 90 and 120 minutes 1.3 grams of sucrose decomposed.
In the first 30 minutes of decomposition, 3 grams of sucrose are lost.
In the next 30 minutes, 2.5 grams of sucrose are lost.
In the next 30 minutes, 2 grams of sucrose are lost.
Thus we can generally state that the rate of decomposition decreases over time.
