A reaction occurs when solid X is placed into solution Y. As a result, the temperature of the new solution increases by
3°C. The temperature rises another 2°C when more of solid X is added to the solution. What does this indicate about
the effect of adding more solid?
It increased the number of molecular collisions.
lt decreased the number of molecular collisions.
It decreased the space between the molecules and lowered the reaction rate.
It increased the space between the molecules and increased the reaction rate.

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

Suppose that during that icy hot lab 65,000 j of energy were transferred to 450 g of water at 20°c what would have have been the final temperature of the water

Compare and contrast physical changes with chemical changes.