30% should be the percentage of oxygen if the total mass of fe2o3 is 160.
An example of an atom that has no charge is one that has a. 2 protons, 2 electrons, and 1 neutron.
To be neutral an atom must have the <em>same number</em> of protons (+) and electrons (-).
Only then will the <em>charges cancel</em> and give a neutral atom.
Answer: 1.32
Explanation:
Given
85 gm of sulfur dioxide is present at STP
The molar mass of sulfur dioxide is 
The number of moles of sulfur dioxide is
1.0×10^−15/4.2×10^−7=<span>2.3809524e-23 Hoped I helped!</span>
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>
