1. The word equation for the reaction between magnesium metal and hydrochloric acid is:
Magnesium + Hydrochloric acid -> Magnesium chloride + Hydrogen gas
2. Sofi a repeated her experiment three times to obtain more reliable and accurate results. By
conducting multiple trials, she can identify any inconsistencies or outliers in her data and calculate the
mean value to get a more representative result.
3. Completed table:
Time in s | Volume of gas collected in cm3
---------------------------------------0
|0 0 0 0
20
| 28 31 31 30
40
| 39 48 42 43
60
| 56 53 57 55.3
80
| 60 59 61 60
100
| 60 59 62 60.3
4. Here is a graph of Sofia's results with a line of best fit:
```
Volume of gas
collected in cm3
70 ┌──────────────────────────────────┐
│
│
│
│
60 ├─┐
││
│
│
50 ├─┼────────────────────────────────┤
││
│
││
│
40 ├─┼────────────────────────────────┤
││
│
30 ├─┼────────────────────────────────┤
││
│
││
│
20 ├─┼────────────────────────────────┤
││
│
10 ├─┼────────────────────────────────┤
││
│
└─┴────────────────────────────────┴──────── Time in s
Reaction Time
```
5. The reaction ends when the volume of gas collected remains constant or does not increase
significantly over a period of time. In Sofia's results, the reaction can be considered to have ended after
100 seconds because the volume of gas collected remains relatively constant at around 60 cm3.
6. The reaction is fastest between 20 seconds and 60 seconds.