%Mass
Ar C = 12 g/mol, Mr C₄H₁₀ = 58 g/mol, Ar H = 1 g/mol
or
Answer: when reactants and products are gases at STP.
Justification:
1) STP stands for standard temperature (0°) and pressure (1 atm).
2) According to the kinetic molecular theory of the gases, and as per Avogadro's principle, equal volumes of gases, at the same temperature and pressure, have the same number of molecules.
3) Since the coefficients in a balanced chemical equation represent number of moles, when reactants and products are gases at the same temperature and pressure, the mole ratios are the same that the volume ratios, and then the coefficients of the chemical equation represent the volume ratios.
Answer:
Fossils tell us when organisms lived, as well as provide evidence for the Fossils are the preserved remains or traces of animals, plants, and other organisms from the past. Fossils, by comparing the anatomies of both modern and extinct species, allows scientists to study the skin, hair, and organs of ancient creatures.
Explanation:
Answer:A mixture is a mechanical combination of several elements or compounds. Mixtures are used in cooking, chemical manufacturing, and a lot of other processes. A good mixture with the materials evenly distributed facilitates a good after mixture process. That might be a chemical reaction or a great cake. One mixture that we see the results of a lot is the mixture of water, gravel, and Portland cement that, after a good mix, becomes concrete. Other mixtures might include the various plastics and epoxies that require two or more parts to become a finished product. There are so many possible mixtures out there I’d suggest chemical engineering books , chemistry books in general, cook books, books on construction processes, and many other possible sources of mixtures and the results of using them.
Explanation:
Answer:
A substance which burns in air and tends to produce heat and light is known as Combustible substances. Non-combustible substances are certain substances which are not combustible in the presence of air. Will not burn on being exposed to flame.
