Fat reacting with sodium hydroxide
Is this a chemical or physical change
My answer is chemical is this right answer
Chemical A originally is buoyant in water; after it mixed with HCI, the new substance now sinks in water.
My answer is physical change. Is this right?
Correct for both!
The first involves a reaction, so it must be chemical. The second involves material change, so it must be physical!
im guessing yes?
Yes, your answer is correct. Fat reacting with sodium hydroxide is indeed a chemical change. When fat reacts with sodium hydroxide (NaOH), a process called saponification occurs, resulting in the formation of soap and glycerol. This reaction involves the breaking and rearrangement of chemical bonds within the fat molecule, leading to the formation of completely new substances with different properties.
In the second example, the change from a substance that is initially buoyant in water to one that sinks after mixing with hydrochloric acid (HCl) is a physical change. In this case, the change in buoyancy is due to the formation of a new chemical compound that is denser than water. However, no new substances are formed, and the change can be reversed by simply separating the original substance from the HCl solution. Therefore, it can be characterized as a physical change.