Please help me out, due today!

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

In a spacecraft, the following reaction occurs: co2(g) + 2lioh(s) -> lico3(s) + h2o(i) (i attached picture of equation) how many liters of carbon dioxide will 4 moles of lithium hydroxide (lioh) absorb? (one mole of any gads occupies 22.4 l under certain conditions of temperature and pressure. assume those conditions for this equation.) 45l 6.0l 3.0l 34l

Which class of molecules functions as chemical signals? hormones water carbohydrates proteins