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Signs of chemical reactions may be: - Gas release - Formation of a precipitate - Change of color - Change of odor - Change of pH - Change of aspect - Change of viscosity - Change of the temperature - Visible formation of new compounds - Change of the state of the matter - A violent reaction with explosion or fire - Bubbling - Emitting a sound - Emitting a light----------------------------------------------------------------
During a physical change the molecule composition is not affected.
What else can I help you with?
What data will you need to determine whether a chemical reaction occurred?
To determine whether a chemical reaction occurred, you will need data such as changes in temperature, formation of new substances, release of gas, and changes in color or odor.
How do you decide whether an observed property of matter is a physical property?
If the property can be observed without changing the chemical composition of the substance, then it is a physical property. If the property can be observed only through a chemical reaction, then it is a chemical property.
Sugar crystals are separated from a sugar syrup by evaporation of water is a chemical reaction or physical reaction?
The separation of sugar crystals from a sugar syrup by evaporating water is a physical process, not a chemical reaction. This is because no new substances are formed during the process—the sugar molecules remain the same whether in the syrup or as crystals.
How do you decide whether an observed property of matter is a chemical property?
If the property can be observed without changing the chemical composition of the substance, then it is a physical property. If the property can be observed only through a chemical reaction, then it is a chemical property.
What is a psyhical reaction?
A physical reaction, or change, is one that can be observed without changing the chemical composition of the substance. Boiling is a physical change because the substance that is boiling does not change its chemical composition. For example, water is still H2O whether it is boiling or not boiling.
Sulfur has a bright yellow color is this physical or cheimical property?
Its colour, its melting point, its boiling point, whether it is magnetic or not, whether it is an electrical conductor or not and its atomic mass are all physical properties.
Explain how you can tell whether a chemical reaction has taken place?
A chemical change or reaction happens if new substances are formed. there may be a change in temperature so the reaction mixture may heat up or cool down. it also might change colour, give off bubbles of gas or fumes and you also might hear fizzing or a gas might explode.
Is it true that production of light is evidence that a physical change may have occurred?
Yes, the production of light can indicate that a physical change has occurred, but it's more commonly associated with chemical changes. In a physical change, light may be emitted due to phenomena like friction or the movement of particles. However, in chemical reactions, light often results from energy release as chemical bonds are formed or broken. Thus, while light production can be a sign of a change, it is not definitive for identifying whether that change is physical or chemical.
How would you determine if a physical change had occurred?
To determine if a physical change has occurred, observe whether the substance retains its chemical composition. Key indicators include changes in state (such as melting or boiling), shape, or size without altering the substance's identity. No new substances are formed in a physical change, so if the original material can be recovered in its original form, it confirms a physical change. Additionally, physical changes are usually reversible, further distinguishing them from chemical changes.
How could you decide whether the dissolving of sugar in water is a physical or chemical change?
You can evaporate the water and recover the sugar unchanged. A chemical change means a chemical reaction has taken place and changed the substance chemically. A physical change means that a solid has become a liquid such as dissolving sugar.
Can indicate physical and chemical changes depending on the cause of the change?
Physical changes involve alterations in form or appearance without changing the substance's chemical composition, such as melting, freezing, or dissolving. In contrast, chemical changes result in the formation of new substances with different properties through reactions, such as rusting or combustion. The cause of the change—whether it be heat, pressure, or a chemical reaction—determines whether the change is physical or chemical. Thus, understanding the nature of the change helps identify the underlying processes involved.
Is reacting with vinegar a physical or chemical property?
Reacting with vinegar is a chemical property because it involves a chemical change where new substances are formed. The reaction between vinegar (acetic acid) and another substance causes a chemical reaction that alters the composition of the original substances.
