Cho 22,8g hỗn hợp A gồm Fe, FeCO3 vào dd HSO, đặc nóng dư thu được 10.08 lít hỗn hợpkhi bay ra (đo ở đktc), biết rằng SO2 là sản phẩm khử duy nhất. Tính % khối lượng của từng chất trong hỗn hợp A ban đầu

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.

plasma - state of matter made up of electrically charged particles