Science Help Please...Chemistry reactions and atoms...?

Question

When you have a barbecue you burn the fuel to produce the heat needed to cook your food. When you have finished you have used up some fuel. But you have not used up the atoms in the fuel-the atoms are still somewhere. They have been conserved.

Q1)
If you used charcoal as the fuel,what happens to the atoms in the charcoal??

2) If you have used a gas barbecue, the fuel is natural gas (methane or butane) What happens to the atoms in a fuel?

3) Explain why, from the point of view of air quality,it is better to "get rid" of garden rubbish by composting rather than burning???

Answer 1

1. The carbon is oxidized to CO2.
2. The fuel is oxidized to CO2 and H2O
3. Composting converts a large amount of garden rubbish to mulch without addition of large amounts of oxygen and the generation of CO2. Also, less energy is used up as water in the rubbish is not vaporized.

Answer 2

Cattbarf is correct.
The charcoal in the fuel is actually elemental carbon. Carbon reacts with oxygen at relatively high temperatures to form carbon dioxide (that is why you need to provide heat, usually in the form of solid fuel to start the reaction) in the equation:
C + O2 --> CO2 (carbon monoxide would be produced is there oxygen is not widely avalible.)
This reaction is exothermic (the reaction gives off or produces heat).
To understand this, atoms are joined together by chemical bonds. Energy is needed, break these bonds (the reason for the solid fuel to kickstart the reaction) for any chemical reaction to occur. On the other hand, energy is given out when new bonds are formed in the chemical reaction. Whether the overall reaction is exothermic or endothermic (takes in heat) depends on the ammount of energy needed to break the bonds of the reactants in comparison to the energy released when new chemical bonds are formed in the reaction.
You are right to say that the fuel atoms are 'conserved' and are still somewhere. The energy produced from burining the fuel did not come from the atoms themselves (if it did, you would have made a nuclear reactor!). Rather, it came from the forming of the chemical bonds in the reaction. The atoms have gone in the air in the form of carbon dioxide (or monoxide)
As to your other questions, natural gas (which contains the elements carbon and hydrogen) reacts with oxygen to from carbon dioxide (or monoxide)(the carbon needs to go somewhere) and dihydrogen monoxide (the facy name for water, the hydrogen needs to go somewhere too!) The water escapes into the atmosphere as water vapour (because of the heat).
As to regards to getting rid of garden rubbish, it is much more environmentally friendly to get rid of it by composting. Firstly, the compost that you produce can be used as an effective fertiliser for your plants (or you can try to sell it!). This is exactly what happens in nature.
Burning it is much quicker. However, it pollutes the air, not only by the carbon dioxide (or monoxide) produced but also by the smoke and it is thus not environmentally friendly and would reduce the air quality). The remenants can be used as backup fertiliser, but is not very effective.
A common misconception is that composting does not produce any carbon dioxide at all. In actual fact, it does as the micororganisms (bacteria, fungi) produce carbon dioxide. However, the ammount produced would be much less than burning the same ammount of garden rubbish.
PS: You can comprimise by burning your garden rubbish in place of charcoal or natural gas as a source of heat. Now THAT would be quite environmentally friendly!

Answer 3

Q1).
Charcoal is an impure form of carbon (C). As charcoal is heated (in a BarBQ) its hot atoms are in contact with the atmophere(O2 & N2).
These hot carbon atoms react with oxygen to form carbon dioxide (CO2), which is released into the atmosphere, because it is a gas. The charcoal lumps will eventually disappear, but because there are impurities in charcoal, the shape of the lump remains. So the carbon atoms in charcoal, are released into the atmosphere as the gas, carbon dioxide.

Q2).
Methane (CH4) and butane (C4H10) react with atmospheric oxygen to form carbon dioxide and water. So the atoms carbon, and hydrogen are released into the atmosphere as carbon dioxide and water. Carbon dioxide is an invisible gas, so you do not see it. Water, when it is formed, is a very hot gas , hotter than steam, so again you do not see it.
Reaction schemes:-
Methane + oxygen = carbon dioxide + water
CH4(g) + O2(g) = CO2(g) + 2H2O(g)

Butane + oxygen = carbon dioxide + water
2C4H10(g) + 13O2(g) = 8CO2(g) + 10H2O(g)

Q3).
By composting garden rubbish, no gas is released, except small amounts of methane, into the atmosphere. Carbon dioxide, CO2, which is a gas would be relased into the
atmosphere, by burning, together with possibly sulphur dioxide, and ammonia. The sulphur and nitrogen components in compost are kept chemically combined as solids or liquids in a compost heap.
Nitrogenous material together with potassium salts and phosphorus compounds are kept inside the compost heap, and when spread back on the ground these nutrients are readily available, for orgaanic growth.
Hence air quality remains high because no polluting gases are released.

NB Under natural processes carbon dioxide is removed from the atmosphere by photosynthesis in plants, and carbon dioxide is readily soluble in water (oceans).

Answer 4

A nuclear reaction is a metamorphosis to the atom's nucleus. Splitting an atom is changing the nucleus, hence, that's a nuclear reaction. Splitting an atom isn't a reason for a nuclear reaction. that's the act of a nuclear reaction. the reason for nuclear reactions is surprisingly much continually instability interior the nucleus of the atom. Atoms attempt to exist in a reliable state, it rather is why we've reactions, and costs, and so on. The atoms attempt to stabilize themselves.