A teacher investigates the rate of reaction between dilute sulfuric acid and magnesium.
The diagram shows the experimental setup:
- The teacher uses five different concentrations of sulfuric acid.
- Each time they react the sulfuric acid with 0.12 g0.12\text{ g}0.12 g of magnesium ribbon.
- They repeat the experiment with 0.12 g0.12\text{ g}0.12 g of magnesium powder.
The table shows the teacher's results:
| Concentration of sulfuric acid (mol/dm3\text{mol/dm}^3mol/dm3) | Time for magnesium to react (s\text{s}s): Magnesium ribbon | Time for magnesium to react (s\text{s}s): Magnesium powder |
|---|---|---|
| 0.2 | 210 | 115 |
| 0.4 | 135 | 72 |
| 0.6 | 78 | 40 |
| 0.8 | 48 | 24 |
| 1.0 | 32 | 14 |
The teacher says that the reaction is faster with magnesium powder than with magnesium ribbon.
Use the results to explain why the teacher is correct.
Describe how the rate of reaction changes when the concentration of the sulfuric acid increases.
Explain your answer to (i) using ideas about particles.
The teacher used 0.12 g0.12\text{ g}0.12 g of magnesium.
0.12 g0.12\text{ g}0.12 g of magnesium reacts with sulfuric acid to make 0.010 g0.010\text{ g}0.010 g of hydrogen gas.
A student suggests that the rate of reaction could be investigated by measuring the loss in mass during the reaction.
Suggest why this method would not work well.
Describe the test for hydrogen gas.
In another experiment, the teacher reacts 0.36 g0.36\text{ g}0.36 g of magnesium with excess sulfuric acid.
Mg+H2SO4→MgSO4+H2\text{Mg} + \text{H}_2\text{SO}_4 \rightarrow \text{MgSO}_4 + \text{H}_2Mg+H2SO4→MgSO4+H2
Calculate the mass of hydrogen gas made.
Relative atomic mass (ArA_rAr): H=1.0\text{H} = 1.0H=1.0, Mg=24.0\text{Mg} = 24.0Mg=24.0