Answer:
Rate depends on the rate constant. The rate constant depends on temperature and activation energy. If you have lower activation energy the rate will be higher. This is why catalysts are added since catalysts provide an alternate pathway that requires lower activation energy and catalysts are added to increase the rate of reaction.
Explanation:
This is only the answer if you were asking:
"Which corresponds to the faster rate: a mechanism with a small activation energy or one with a large activation energy?"
Thats what I understood about your question.
Answer:
The mass was there all along, it was just in the air. The weight of the oxygen from the air is not weighed in the beginning, only at the end as part of the product, making it seem like there is a total mass change.
This is a hard question because BEING BOLD cant be light ya know... but the light bulb.. thomas edison and joseph swan