Equations and amounts · Grade 10
The relative atomic mass of magnesium
ChemAI · Worksheet
NameClassDate
Aim
Weigh a magnesium ribbon, collect the hydrogen it makes and calculate Ar(Mg).
Before you start: what do you predict will happen? Why?
What you do
| Step | What I observed | |
|---|---|---|
| 1 | Add the weighed magnesium ribbon to the acid. Note its mass. | |
| 2 | Wait until all the magnesium has reacted (×5). Read the volume of hydrogen. | |
| 3 | Calculate: n(H₂) = V ÷ 24 000 mL/mol = n(Mg); Ar = m ÷ n. Check your answer in the observations. | |
| 4 | Calculate Ar(Mg) = m ÷ (V ÷ 24 000) from your mass and volume. |
Calculation
Calculate Ar(Mg) = m ÷ (V ÷ 24 000) from your mass and volume.
Questions
- Write a word or symbol equation for one reaction you observed.
- Explain your most important observation using particles, ions or energy.
- Was your prediction right? What would you change to get a more reliable result?