Solid calcium carbonate is added to 100 cm³ of dilute hydrochloric acid and the rate of the reaction is measured. 100 cm³ of distilled water is then added to a second 100 cm³ portion of the acid, and the experiment repeated under the same conditions. Why does the addition of water decrease the rate of the reaction? 1 Adding water reduces the frequency of collisions between reactant molecules. 2 Adding water reduces the proportion of effective collisions between reactant molecules. 3 Adding water reduces the proportion of reactant molecules possessing the activation energy.

Which statement about the effect of a catalyst on a reversible reaction is correct?

Some polluting gases are removed from car exhaust fumes using a catalytic converter. Platinum or palladium can be use…

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A chemist took 2.00 dm³ of nitrogen gas, measured under room conditions, and reacted it with a large volume of hydrog…

A carbonyl compound X will react with HCN in the presence of NaCN to make a compound with Mr 85. Compound X does not …