Table of Contents
- 1 What evidence occurs during a chemical reaction?
- 2 What evidence of a chemical reaction can be observed at the macroscopic scale?
- 3 Which observation would provide the best evidence that a chemical reaction occurred?
- 4 What are the macroscopic indications of a chemical reaction?
- 5 What is the scientific view of chemical reactions?
- 6 Are there any rules for predicting chemical reactions?
What evidence occurs during a chemical reaction?
Evidence of a chemical change Change of odor. Change of color (for example, silver to reddish-brown when iron rusts). Change in temperature or energy, such as the production (exothermic) or loss (endothermic) of heat. Change of composition – paper turning to ash when burned.
What is a microscopic reaction?
On the microscopic level, a chemical reaction involves transformation of reactant atoms, ions, and/or molecules into product atoms, ions, and/or molecules. This requires that some bonds be broken, other bonds be formed, and some nuclei be moved to new locations.
What evidence of a chemical reaction can be observed at the macroscopic scale?
In the laboratory macroscopic observations are used to infer changes at the particulate level. Evidence for chemical change include gas production, change in temperature, change in odor, change in color, and formation of a precipitate.
What is microscopic in chemistry?
In the context of Chemistry, “microscopic” implies the atomic or subatomic levels which cannot be seen directly (even with a microscope!) whereas “macroscopic” implies things that we can know by direct observations of physical properties such as mass, volume, etc.
Which observation would provide the best evidence that a chemical reaction occurred?
A chemical reaction is usually accompanied by easily observed physical effects, such as the emission of heat and light, the formation of a precipitate, the evolution of gas, or a color change.
What is microscopic process?
Optical or light microscopy involves passing visible light transmitted through or reflected from the sample through a single lens or multiple lenses to allow a magnified view of the sample. The resulting image can be detected directly by the eye, imaged on a photographic plate, or captured digitally.
What are the macroscopic indications of a chemical reaction?
A chemical change has probably occurred if the following can be observed on the macroscopic level:
- bubbles are released (a new gas is formed)
- there is a change of color.
- a new odor is produced (a new gas is formed)
- heat, loud, or soud is released.
- a new solid forms.
How to tell if a chemical reaction has taken place?
When a physical change occurs there is no breaking and forming of bonds. There are certain things that will help us identify if a chemical reaction has taken place. In a chemical reaction this energy is changed when old bonds are broken and new bonds are formed.
What is the scientific view of chemical reactions?
Scientific view. All materials are made of chemicals. Chemical reactions involve interaction between chemicals such that all reactants are changed into new materials. The properties of the new materials are different from those of the reactants.
When do new substances form in a chemical reaction?
A chemical reaction happens when substances break apart or combine to form one or more new substances. New substances form when bonds break and new bonds form. The chemical properties of the new substances are different from those of the original substances.
Are there any rules for predicting chemical reactions?
Rules for balancing equations: It is possible, however, to predict the products of some chemical reactions. To achieve this, you must be able to recognize various types of reactions. Five general types of reactions are: composition, decomposition, single replacement, double replacement, and combustion.