Hess's law states that: A. The overall enthalpy change for a reaction is independent of the route the reaction takes. B. Energy cannot be created nor destroyed, it can only change form.
O C. When the enthalpy changes under standard conditions, 1 mole of a substance is formed
from its elements.
O D. The enthalpy change when 1 mole of a substance undergoes complete combustion under
standard conditions is equal to molar masses of the compounds.

Malik formed a hypothesis that an increase in atmospheric oxygen levels by 10% would cause red-legged grasshoppers to grow larger than normal. suppose that malik performs an experiment to test his hypothesis. which of these actions would represent a scientific mistake in his experiment? a. he experiments on live grasshoppers instead of preserved ones. b. he focuses on red-legged grasshoppers instead of all kinds of grasshoppers. c. he varies the nitrogen and carbon dioxide levels in the air from one trial to the next. d. he conducts the experiment in a controlled lab setting with a lab partner. e. he measures the mass and length of his specimens at the start of each trial.