Cho hỗn hợp rắn X gồm KCl, MgCl2 và NH4Cl. Hòa tan 27,65 gam hỗn hợp X vào nước rồi cho tác dụng với dung dịch NaOH(dư) thì số mol NaOH phản ứng là 0,4 mol. Mặt khác, nếu hòa tan 0,6 mol hỗn hợp X vào nước rồi cho tác dụng với lượng dư dung dịch Na2CO3, thu được 12,6 gam kết tủa. Tính phần trăm khối lượng KCl có trong X.

Achemical reaction (also known as a chemical change) produces substances that are chemically different from the starting materials. an example of a chemical reaction is the formation of water from hydrogen and oxygen gas. in a physical change, a substance changes its physical appearance but not its chemical identity. an example of physical change is the formation of liquid water from solid water, a familiar process called melting. physically, liquid water looks very different from solid water (ice) but the chemical identity, water, is the same for both. which of following changes that affect the composition of our atmosphere involve physical changes and which involve chemical reactions? oxygen gas changes to ozone during thunderstorms carbon dioxide is produced by the combustion of gasoline in an automobile engine. when coal, oil, and natural gas are decomposed in landsills they produce methane gas. freezing rain develops when a warm air mass overrides a cold air mass. fog forms from water vapor when the temperature drops below the dew point

The best solution for preventing harm to people and pets from severe hurricanes involves determining and warning residents about what

Ants live on acacia trees in south america. the ants feed on sugars secreted by the trees. the trees provide room for the ants to live. the ants sting any other insect or animal that comes to eat the trees. what type of relationship is this?