A science teacher asked three groups of students to prepare pure water by combining hydrogen and oxygen. Each group used different quantities of the elements. After the experiment, the teacher asked the students to compare the mass ratio of hydrogen and oxygen in each sample.
The observations are given below.
| Group | Hydrogen (\(g\)) | Oxygen (\g\)) |
| A | 2 | 16 |
| B | 5 | 40 |
| C | 7 | ? |
The teacher reminded the students that a pure compound always contains the same elements combined in a fixed mass ratio, irrespective of the amount prepared.
Answer the following questions with the appropriate answer.
1. Which law is illustrated by the above investigation? -
2. Suppose Group C actually used only 50 g of oxygen. Which statement is correct? -