Bronwyn completed the same chemical reaction four times. She weighed the amount of chemical produced by each experiment. Which result would show that the experiment is valid?

If the weight of chemical is same so it represent that the experiment is valid.

Explanation:

If Bronwyn performed the same chemical reaction four times and she measure the weight of chemical with the help of electrical weight balance so if she find out the weight of the chemical that is produced during four experiments then we can say that the experiment is valid because the experiment was performed four times and that is enough for validation of the experiment.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.