Methane is the compound CH4, and burning it uses the reaction:
CH4 + O2 -> CO2 + H2O, which is rather exothermic. To find the heat released by burning a certain amount of the substance, you should look at the bond enthalpy of each compound, and then compare the values before and after the reaction. In methane, there are 4 C-H bonds, which have bond energy of 416 kj/mol, resulting in a total bond energy of 1664 kj/mol. O2 is 494 kj/mol. Therefore we have a total of 2080 kj/mol on the left side. On the right side we have CO2, which has 2 C=O bonds, each at 799 kj/mol each, resulting in 1598 kj/mol, and H2O has 2 O-H bonds, at 459kj/mol each, resulting in a total of 2516 kj/mol on the right hand side. Now, this may be confusing because the left hand side seems to have less heat than the right, but you just need to remember: making minus breaking, which results in a total change of 436kj/mol heat evolved.
Now it is a simple matter of find the mols of CH4 reacted, using n=m/mr.
n = 9.5/16.042 = 0.592195 mol
Therefore, if we reacted 0.592195 mol, and we produced 436 kj for one mol, the total amount of energy evolved was 436*<span>0.592195 kj, or 258.197 kj.</span>
Brass is an alloy, or a combination of two (or more) metals.
You kind of need to show more, but the independent variable would be something that you are changing to then measure the reaction, like the time left in for example.
The reaction is a double displacement one which means the cation of one reactant is substituted to the cation of the other reactant to identify the products. Hence in this reaction, the products are silver ammonium nitrate (Ag(NH3)2NO3) and hydrochloric acid (HCl).
Answer:
D.<em> </em>Radiation
<em>Explanation:</em>
The Sun always transfers its energy to any planet (Including Earth) through <u>solar radiation, infrared, and UV rays.</u> These are all examples of <u>radiation.</u>
I hope this helps you! Good luck with your test/assignment! :D
