Chemistry questions, there is addition, chemistry problems are added!

The production can be used as a gas (NE) to fill fluorescent lamps

Scientific research, for example, particles can be used as rays (HE).

Production: Crafting neon signs, which act as protective gas.

Scientific research: fabrication of a variety of mixed gas lasers.

He, do experiments, punch balloons, light bulbs into the astronaut's body to resist weightlessness.

Gas filling in food, such as gas in potato chips.

Production: shielding gas. For example, argon is often used as a shielding gas in the welding of precision parts or reactive metals such as magnesium and aluminum, as well as in the manufacture of semiconductor transistors.

Plutonium, the nuclear fuel of an atomic reactor, also oxidizes rapidly in the air and also needs to be mechanically processed under the protection of argon. Filling the bulb with argon gas can reduce the vaporization of tungsten filament and prevent tungsten filament oxidation, so as to prolong the life of the bulb.

Scientific research: A variety of mixed-gas lasers can be made from the use of rare gases. ......

Neon: For light bulbs.

Helium: It can be used as a new type of nuclear fuel and can also be used as a substitute for hydrogen balloons.

It is obtained from PV=NRT: the same temperature and pressure, which means that the volume is only related to the quantity of the substance, and it is proportional (1) The mass is the same, and the relative molecular mass of the two is 1:2, then the ratio of the quantity of the two substances is 2:1, that is, the ratio of the molecular number of H2 to HE is 2:1

2) At the same temperature and pressure, when the volume is the same, the amount of the substance is also the same, because the relative molecular mass of the two is 1:2, so the mass ratio of H2 to HE m n=1:2<1

3) Multiply the molar mass M on both sides of the PV=NRT equation to obtain MPV=mnrt=MRT, so the density = MP RT, the same temperature and pressure, the density ratio is equal to the ratio of the relative molecular mass, that is, 1:2

All three options are wrong.

Molar mass: H2 2 g mol, He 4 g molmgH2 and NGHE The following statements are true.

a.At the same temperature and pressure, if m=n, the ratio of the number of molecules of H2 to HE is 1:1, which has nothing to do with "at the same temperature and pressure", and it can be seen that it should be 2:

1b.At the same temperature and pressure, at the same volume, the mass ratio of H2 to HE m n>1 can be seen to be M n=1 2

c.At the same temperature and pressure, the density ratio of H2 to HE is 1:1, and it can be seen that it should be M n=1 2

There is no right answer.

It seems to be dilute sulfuric acid CO32-+2H+==H2O+CO22, BaCl2 Ba2++SO42-==BaSO4 3, iron powder Fe+Cu2+==Fe2++Cu4, dilute hydrochloric acid CO32-+2H+==H2O+CO2

CaCO3 == (high temperature) CaO+CO2 gas.

CO2 + C = = (high temperature) 2CO

2CO+O2== (ignition) 2CO2

2cao+2co2== (high temperature) 2caCO3 was originally one part, and later it was two, so 2:1

caco3=cao+co2

co2+c=2co

2co+o2=2co2

CO2 + Ca(OH)2 = CaCO3 + H2OC is doubled in the second step, so the result is 2:1 from the original