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>
Explanation:
While both developed and developing countries have contributed to global environmental problems, developed countries with 85% percent of the gross world product and 23% of its population account for the largest part of mineral and fossil-fuel consumption, resulting in significant environmental impacts
Answer: Option (D) is the correct answer.
Explanation:
When heat or energy is transferred through the space in the form of waves or through a material medium then it is know as radiation.
For example, when we take Sun bath then our body gets warm due to solar radiation.
For transfer of heat through radiation it is not necessary that the objects have to in contact with each other.
Thus, we can conclude that out of the given options, the transmission of heat without any contact.
<span>The radioisotope used to date rock formations 50 000 years ago is Uranium. This radioactive uranium isotope having a mass number of 235 and its symbol is U, its atomic number is 92, and the mass number is 238, comprising 0.715 percent of natural uranium. When bombarded with neutrons it undergoes fission with the release of energy.</span>
Answer:
Sequence
Explanation:
Physical properties of the proteins are foundation of biological function of them.
A protein molecule is made up from the long chain of the amino acids. Each amino acid is linked to its neighbor by covalent peptide bond. Thus, proteins are also called as polypeptides.
Each protein has unique sequence of the amino acids, exactly same from one molecule to next. Different proteins has its own particular sequence of amino acid. This sequence is responsible for folding and binding of the protein and also its physical characteristics.
