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 correct answer is A Energy leaves the iron bar and enters the wood until the temperature are equal.
Explanation:
According to the law of conservation of energy or the first law thermodynamics energy neither be created nor destroyed, energy is transferred from one form to another form.
Here iron bar is placed in wood block energy is transferred from iron bar to wood until the temperatures are equal.
Answer: yes even temperature too in rarely case
The unit cm3 is used to express a cube using cm
Answer:
No
Explanation:
Droplets or aerosols. When an infected person coughs, sneezes, or talks, droplets or tiny particles called aerosols carry the virus into the air from their nose or mouth. Anyone who is within 6 feet of that person can breathe it into their lungs.
Airborne transmission. Research shows that the virus can live in the air for up to 3 hours. It can get into your lungs if someone who has it breathes out and you breathe that air in.
Surface transmission. Another way to catch the new coronavirus is when you touch surfaces that someone who has the virus has coughed or sneezed on. You may touch a countertop or doorknob that's contaminated and then touch your nose, mouth, or eyes. The virus can live on surfaces like plastic and stainless steel for 2 to 3 days. To stop it, clean and disinfect all counters, knobs, and other surfaces you and your family touch several times a day.
Fecal-oral. Studies also suggest that virus particles can be found in infected people's poop. But experts aren't sure whether the infection can spread through contact with an infected person's stool. If that person uses the bathroom and doesn't wash their hands, they could infect things and people that they touch.
