There are more particles.
The volume is larger.
The particles have more energy
There are more particles per unit volume.
50 cm3 of 1.0 mol/dm3 hydrogen peroxide were used in experiment X while 25 cm3 of 2.0 mol/dm3 of hydrogen peroxide were used in experiment Y
1.0 g of catalyst was used in experiment X while 0.50 g of catalyst was used in experiment Y.
Experiment X was carried out at 60 deg celsius while experiment Y was carried out at 30 deg celsius.
50 cm3 of 1.0 mol/dm3 hydrogen peroxide was used in experiment X while 12.5 cm3 of 2.0 mol/dm3 were used in experiment Y.
1 mol/dm3 of HCl
2 mol/dm3 of citric acid, a tribasic acid
1 mol/dm3 of H2SO4
0.5 mol/dm3 of H2SO4
Using 0.5 g of granulated zinc
Using 1 g of finely powdered zinc
Warming the acid to 40 °C.
Adding water to dilute the acid