I believe the correct answer would be that t<span>he change in enthalpy can be found by adding the enthalpies of the individual thermochemical reactions of a chemical reaction.</span> In Hess' Law, enthalpy is independent of the mechanism of the reaction. The enthalpy should be the sum of all the changes in the reaction.
<h2>Answer:</h2>
The phase of matter will be known as the forth phase of matter, plasma.
<h3>Explanation:</h3>
There are 4 phases of matters:
- Gas: The freely moving molecules, having no definite volume and shape.
- Liquid: The loosely bonded molecules, having a definite volume but not shape.
- Solid: Highly packed molecules with definite volume and shape.
- Plasma: The more like gases phase, containing freely moving electrons and positive ions.
Hence according to the question description and given above matter phases, the phase of that sample will be plasma.
The answer is -60.57. With appropriate sig figs it becomes -60.6 KJ.
<span>I think you were on the right track. However you need to multiply H2O by its coefficient from the balanced equation. Then you also need to keep in mind the signs. </span>
<span>Maybe it's easier if I write what I did out: </span>
<span>2H2O > 2H2 +O2...............-H= 2* -285.83 </span>
<span>Ca + O2 + H2 > Ca(OH)2....H= -986.2 </span>
<span>2C + H2 > C2H2.................H= 226.77 </span>
<span>The above H's stand for standard enthalpy of formations. These can be found in textbook appendix. Notice the negative infront of the enthalpy (H) for H2O. This is to remind me/you that the heat lost is gained in the rxn. </span>
<span>So then you add them up. 226.77 - 986.2 + (2*285.83) = -187.77 </span>
<span>Add back the total enthalpy that is given in the question -187.77+127.2 = -60.57 </span>
<span>If signs cross you up find a way to remember that works for you. </span>
You just need to multiply the total mass by the decimal value of the part that is tin. 133.8*0.103=13.8g (following the rules of significant figures).
