I would say the first three. But I'm not 100% sure. I'm truly sorry if it's wrong
Answer:
I believe is A
Explanation:
Enthalpy change is the name given to the amount of heat evolved or absorbed in a reaction carried out at constant pressure.
The matter wasn't destroyed because albert einsteins theory of the black hole says that matter cannot be destroyed if it is burned into the same color of a black hole. this eqation proves my thesis:
²²↑↑Ф
Answer:
a. The student performed the splint test incorrectly. He should of observed a popping sound when the splint was placed in the test tube.
Explanation:
It is given that a student performed an experiment where he dropped a nickel metal in to HCl solution. He observed the reaction and performed a splint test in the test tube that is filled with a gas which is formed while Nickle is dropped into the solution of HCl.
But the experiment that the student performed was incorrect. He must have observed the popping sound when the splint was placed in the test tube.
When the splint was added to the gas splint flared up. The hydrogen gas pops out when exposed to the flame.

Thus the correct option is (a).
Answer:
6 moles of Cl2
Explanation:
First, the equation has to be balanced, which makes it 4 FeCl3 + 3 O2 --> 2 Fe2O3 + 6 Cl2
Using this information, we can see that one mole of O2 will not be present in the reaction. Since four moles of FeCl3 are needed to react in the equation, which would produce six moles of Cl2, and only four moles of FeCl3 are present, six moles of Cl2 would be produced.