What test is used to compare soil samples using equal amounts of soil samples (a control and unknown) and placed in varying levels of liquids?
a) titration test
b) ultraviolet test
c) density gradient tube test
d) comparison microscope test

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

C3h8o3 - glycerol major species present when dissolved in water

Consider the equilibrium system: 2icl(s) ⇄ i2(s) + cl2(g) which of the following changes will increase the total amount of of cl2 that can be produced? all of the listed answers are correct decreasing the volume of the container removing the cl2 as it is formed adding more icl(s) removing some of the i2(s)