14 A 5-g sample of impure magnesium carbonate is reacted with an excess of hydrochloric acid:
MgCO2 (s) + 2HCl (aq) →
MgCl, (aq) + H, O (1) + CO, (g)
1250 cm of carbon dioxide is collected at rtp.
a How many moles of CO2 are produced?
b What mass of pure magnesium carbonate would
give this volume of carbon dioxide?
(A.: C = 12, O = 16, Mg = 24.)
c Calculate the % purity of the 5-g sample.

How does a catalyst increase the speed of a reaction? a. the catalyst eliminates the activated complex stage, allowing products to form immediately. b. the catalyst lowers the energy level of the reactants, making it easier for them to react. c. the catalyst makes it easier for the activated complex to form, lowering the activation energy. d. the catalyst raises the energy level of the products, making the reaction finish sooner. reset next