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>
Answer:
The dam disrupts the river wildlife and ecosystem.
Explanation:
Though it is believed that using the dam as a power generation or hydroelectric power supply generates no greenhouse gases, it, however, has many disadvantages which make it deemed not suitable or sustainable for use in the contemporary time.
Majorly, the top reason why more hydroelectric dams are not built is that "the dam disrupts the river wildlife and ecosystem."
Also, it affects the water quality and other use of water for humans such as recreational use.
There is also a possible chance of dams producing methane; a greenhouse gas through the organic materials in the water that is rotting.
Answer:
0.025536g
Explanation:
no. of mole = mass/Mr
mass = Mr × no. of mole
= [23 + 1 + 12 + 3(16)] × 3.04×10^-4
= 0.025536g
= 0.0255g (3 significant figures)