According to the balanced equation from Experiment 8 for the produced hydrogen gas, if 12.0 L of hydrogen gas was collected over water at 20.0 °C and 821 torrs, how many grams of Mg must have reacted? (R = 0.0821 L atm/ mol K) ​

Group of answer choices

12.5 g

12.8 g

13.0 g

12.7 g

a. a primary source combines several different accounts of an event. b. a primary source generally benefits from having been written after an event.

explanation:

the potential energy of the reactants is 200j.

from the energy diagram, the energy of the product formed is 350j; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.

a is the correct answer