Why is mercaptan often added to civil gas?

The gas has no smell. The addition of mercaptan gives alertness (the smell of mercaptan).

Since gas (CO) itself has no odor, what about piped gas and LPG used for cooking that have an unpleasant odor? In fact, the main components of coal gas ——— carbon oxide, methane or hydrogen, which are all colorless and odorless gases. The main components of liquefied petroleum gas, propane, butane, propylene, and butylene, have a bit of a gasoline-like smell, but they are not very smelly.

If there is no smell, if there is a gas leak, people don't know if there is gas in the air, and they don't know if they are poisoned. If there is a smell, it can make people alert, and soon find that the air leak is leaking, and measures can be taken immediately to prevent the occurrence of **, fire and poisoning accidents. So what kind of substance can act as a "odor alarm"?

Studies have found that mercaptans could not be better at playing this role. Mercaptan is a foul-smelling substance. People's sense of smell is very sensitive to the foul smell of mercaptans.

Therefore, factories that produce gas and liquefied petroleum gas deliberately add a little bit of this surprisingly smelly alcohol and sulfur to the fuel gas to act as an odor alarm, so that when they smell this odor, they can detect a gas leak as soon as possible, and they can take measures to prevent disasters from occurring.

For safety, because pure gas is colorless and odorless, it is generally difficult to be found in the case of gas leakage, and it is easy to have safety problems.

The addition of mercaptan to the gas does not neutralize the toxic gas, but it is only to make it easier to detect the gas leak so that remedial measures can be taken or evacuated, because the slightest amount of mercaptan can be sniffed out.

Coal gas is a gas containing flammable components that is processed from coal. According to the processing method, the nature and use of the gas, it is divided into: water gas, semi-water gas, air gas (or furnace gas) obtained by coal gasification, and the calorific value of these gases is low, so they are also collectively referred to as low calorific value gas; The gas obtained by coking in the coal dry distillation method is called coke oven gas and blast furnace gas.

It belongs to the medium calorific value of gas, which can be used as a civil fuel in the city. Carbon monoxide and hydrogen in coal gas are important chemical raw materials.

From the chemical equation in the question stem, it can be seen that there are 4 carbon atoms, 12 trillion hydrogen atoms, 2 sulfur atoms and 18 oxygen atoms on the left side of the equation, and 4 carbon atoms, 12 hydrogen atoms, 14 oxygen atoms and 2 x molecules on the right side According to the prudent characteristics of the law of conservation of mass in which the type of elements and the number of atoms remain unchanged, it can be seen that 2 x molecules contain 2 sulfur atoms and 4 oxygen atoms, that is, 1 x molecule contains 1 sulfur atom and 2 oxygen atoms, so the chemical formula of x is SO2

Therefore, c

According to the chemical equation 2c2 for the combustion of ethyl mercaptan

h5sh+9o2

Ignite 4CO2

2r+6h2

The law of constancy of o and mass holes shows that the number of atoms of element c contained in the chemical formula of r is (2 2-4) 2=0, and the number of atoms of element o is (2 9-2 4-6) 2=2.

The number of primordial reflexes of element h is: (6 2-2 6) 2=0, and the number of atoms of element s is: 2 2=1, so the chemical formula of r is: SO2

So choose A

According to the chemical equation of ethyl mercaptan combustion, 2C2H5SH+9O2 is ignited

4CO2+2R+6H2O and the law of conservation of mass show that the number of atoms of element C contained in the chemical formula of R is (2 2-4) 2=0, the number of atoms of element O is (2 9-2 4-6) 2=2, the number of atoms of element H is: (6 2-2 6) 2=0, the number of atoms of element S is: 2 2=1, so the chemical formula of R is: SO2

So choose A

The chemical equation by which the reaction is 2c2

h5sh+9o2

Ignite 4CO2

2x+6h2

o, according to the law of conservation of mass, the number of atoms before and after the reaction should be equal, before the reaction: 2 s, then after the reaction x should have 2 s primitives, before the reaction there should be 18 o, and after the reaction there are 14 o, then x has a total of 4 o atoms, the number of hydrogen atoms before and after the reaction is 12, and the stoichiometric number of x is 2, then the chemical formula of x is so2

The main component of gas is carbon monoxide, carbon monoxide has no odor, and ethyl mercaptan has a special smell, so the purpose of adding ethyl mercaptan is to allow people to detect gas leaks in time

So the answer is: SO2

the law of conservation of mass; Detect gas leaks in a timely manner

by 2c2h5sh+9o2

Ignite4CO2+2x+6H2O shows that there are 4 carbon atoms before the reaction and 4 after the reaction.

There are 12 hydrogen atoms before the reaction and 12 after the reaction;

2 sulfur atoms before the reaction, 2 after the reaction should be, contained in 2x;

The oxygen atoms before the reaction are 18 and after the reaction should be 18, of which 4 are contained in 2x;

From the analysis, it can be seen that each X contains 1 sulfur atom and 2 oxygen atoms, which is sulfur dioxide, and the chemical formula of sulfur dioxide is SO2

Therefore, c