to tell if a chemical reaction has occurred look for these four things:
1) color change
2) the formation of gas bubbles
3) formation of a precipitate
4) temperature change
precipitation
evolution of gas
change of odor
change of color
change of viscosity
change of temperature
change of pH
visible formation of a new compound
im sorry bout the language people put on here its glow smoke burn fire
Dissolving salt in water is a physical change- no chemical reaction took place. If the water evaporates, the salt is still there.
The solution becomes cloudy due to the formation of calcium carbonate, a white solid.
lop
chemical reactions took place when labrotary experimentories.
A change in state. It can always be changed back into its origanal state. (Ex. Melting, boiling, evaporation, freezing) Other ex. melting butter, shredding paper, mowing the grass, or liquid water to ice
caramelization :D
taulom
When a compound undergoes a chemical reaction, its chemical bonds are broken and reformed to result in new substances with different chemical properties. This process can involve changes in energy, formation of new bonds, and rearrangement of atoms. The reactants are transformed into products through the rearrangement of atoms.
A chemical reaction took place creating a new element.
Bubbles
Evidence of a chemical reaction includes the formation of a new substance with different properties, changes in color, the release of gas or heat, or the formation of a precipitate. Additionally, changes in mass due to the rearrangement of atoms in the reactants can also indicate a chemical reaction has occurred.
"New substances" is a vague description of what happens in a chemical reaction. Simply put though, yes. An example of this would be if you took baking powder and vinegar and mixed them together, the resulting chemical reaction would create Carbon Dioxide. That is a new substance, it wasn't there until the reaction took place.
1. Initial substances in a chemical reaction are called reactants.2. The obtained final substances are called products or resulting substances.
Dissolving salt in water is a physical change- no chemical reaction took place. If the water evaporates, the salt is still there.
it is an ionic and exothermic reaction i.e. when it will take place heat will be liberated
The evidence that a chemical reaction took place when silver nitrate was mixed with ammonium chloride is the formation of a white precipitate of silver chloride. This indicates that a chemical reaction occurred between the silver ions from silver nitrate and the chloride ions from ammonium chloride, resulting in the insoluble silver chloride. Additionally, the solution may turn cloudy or there may be a color change, further supporting the occurrence of a chemical reaction.
Evidence that a chemical reaction took place when zinc mixed with HCl includes the production of hydrogen gas bubbles, formation of zinc chloride as a product, and an increase in temperature of the reaction mixture due to the exothermic nature of the reaction. Additionally, the disappearance of the solid zinc as it undergoes dissolution is another indication that a chemical reaction has occurred.