A student carries out an experiment to investigate the rate of reaction between excess marble chips (CaCO3\text{CaCO}_3CaCO3) and 50 cm3 of 2.0 mol dm-3 hydrochloric acid (HCl\text{HCl}HCl).
Which of the following changes to the reaction conditions would result in a decrease in the initial rate of reaction?
Using the same mass of marble chips as a fine powder rather than medium-sized chips
Using 100 cm3100\text{ cm}^3100 cm3 of 1.0 mol dm−31.0\text{ mol dm}^{-3}1.0 mol dm−3 HCl(aq)\text{HCl(aq)}HCl(aq) instead of 50 cm350\text{ cm}^350 cm3 of 2.0 mol dm−32.0\text{ mol dm}^{-3}2.0 mol dm−3 HCl(aq)\text{HCl(aq)}HCl(aq)
Heating the reaction mixture from 293 K293\text{ K}293 K to 308 K308\text{ K}308 K
Using 100 cm3100\text{ cm}^3100 cm3 of 2.0 mol dm−32.0\text{ mol dm}^{-3}2.0 mol dm−3 HCl(aq)\text{HCl(aq)}HCl(aq) instead of 50 cm350\text{ cm}^350 cm3 of 2.0 mol dm−32.0\text{ mol dm}^{-3}2.0 mol dm−3 HCl(aq)\text{HCl(aq)}HCl(aq)
