Since we're talking about wrong statements, in the explanation for this chapter (sorry, I can't report mistakes there) there is a sentence on the "при" section which is wrong.
"При э́той температу́ре газ бы́стро расширя́ется. = At that temperature, the gas expands rapidly." Gases (ideal ones anyway, and the general public wouldn't find a situation where they would behave different) expand linearly with the temperature. This means that there is no such thing as a temperature at which a gas will start expanding faster (unless the substance decomposes, but that's another thing). The sentence should be changed to something like "At that temperature, the gas condenses" or "At that temperature, the substance boils" or whatever.
PS - I know that the sentence is grammatically correct, but I don't think it needs to be factually incorrect just to have an example.
But the sentence is factually correct too. Consider how it doesn't say that the gas is expanding as temperature increases, or how it's phrased in absolute terms - notice how it's быстро and not быстрее. In fact, gases at a certain temperature expanding rapidly is a very quotidian thing. For example, it happens several times a second inside a car's engine.
A gas at a certain temperature doesn't expand. Gases expand or contract in volume (at a certain pressure) when they heat up or cool down. The formula PV=nRT (which applies to ideal gases, but normal gases under not too extreme temperatures or pressures can also be considered ideal) indicates that for a certain pressure and temperature the volume of a gas depends only on the number of molecules (R is a constant). In other words, gases expand or contract due to variations of pressure or temperature. That's it. A car engine isn't exactly a good example either. You have a substance (gasoline) that is ignited. For the sake of simplicity let's assume gasoline is just octane, which it isn't but doesn't change the answer much. The chemical reaction between the gasoline and oxygen has two effects that are worth considering for the case we're discussing: 1) The number of molecules for a full combustion at the beginning is 27 (two C8H18 for twenty five O2). At the end of the combustion it's 34 (16 CO2, and 18 H2O). The difference is 7 molecules. Since we have 7 more molecules at the end, per the formula above, the volume upon reaction would be bigger (7/27 = 26% bigger). But this is hardly important since; 2) The reaction of the gasoline with air is extremely exothermic. It produces so much heat (i.e. the temperature increases so much) that the gas is not at a certain temperature. It rapidly increases in temperature, thus increasing in volume.
Say as much as you want, the sentence is wrong.
Here we go again...
Gases change their volume upon changes of either pressure or temperature. If you change the pressure, saying "At that temperature, the gas expands rapidly." makes no sense, because the temperature is not involved at all. At a certain temperature, gases don't expand. Period!
That sentence is as correct as "With that amount of salt, ketchup tastes better if it doesn't have any strawberries." The sentence itself is grammatically correct, but if someone said that to you you'd think: what did this guy smoke?