Matter undergoes three changes: physical, chemical and nuclear. Although when carrying out a chemistry experiment, the composition of chemical substances is not changed by physical changes (such as freezing and evaporation), chemical changes or reactions change, resulting in the formation of new substances when bonds form and/or break.
Some relatively simple but common types of chemical reactions are described in this experiment. Examples and descriptions of each type of reaction are shown in the following section.
We conduct Chemical experiments to perform and observe the results of various reactions
When performing any chemistry experiment various things must be taken into consideration for a successful result. These include;
* Familiarize yourself with observable signs of chemical reactions.
* Identify products formed in chemical reactions and predict when reactions will occur.
* Write equilibrium equations for the reaction studied.
* Use the results from a single replacement reaction to design a part of the Active series.
Things to look out for when carrying out a Chemistry Experiment
* Colour variations.
* Formation of precipitates-indicated as the formation of turbid solutions, the formation of gels or noticeable solids.
* Evolution of the gas-note bubbling in the solution.
* The emergence or disappearance of significant separation between two or more liquids.
* Evolution of heat-noted as the temperature increases.
* Absorption of heat-noticed as the temperature drops.
* Plating out one metal in another.
* Decomposition, pitting or disappearance of solid metal
TYPES OF CHEMISTRY EXPERIMENTS
Combination reaction occurs when two or more substances, elements, or compounds combine to form a new substance, a (also known as a synthetic reaction).
The decomposition reaction occurs when the compound decomposes to produce two or more new substances.
Displacement reaction (also known as a single displacement reaction) involves one element in a compound is replaced by another element.
Substitution reactions are also classified as redox reactions. The ability of one metal to replace another depends on their relative ease of oxidation—more active metals (metals that are easier to oxidize) replace less active metals.
An exchange reaction (also known as a double displacement or metathesis reaction) occurs when two compounds form an ion exchange partner in the reaction of ions in solution. The occurrence of these reactions must meet one of three conditions:
(1) the formation of insoluble ionic compounds, precipitation is observed,
(2) the formation of gases.
(3) the production of water from hydroxide ions and hydrogen ions (examples of acid-base neutralization).
In each case, one of the products is removed from the solution by the reaction by combining two ions. When the aqueous solution of the two ionic compounds are mixed and Ion-bound so that the water-insoluble compound (precipitation, the reaction used in some commercial water softeners), the precipitation reaction occurs
HOW TO CARRY OUT AN EXPERIMENT
*Establish a scientific question and understand how to answer it through experiments
*analyze the data to draw a scientific conclusion)
*collect scientific data through safe and correct chemical experiments
*describe attributes or events in a way that does not depend on numbers through laboratory reporting
Observations can be qualitative or quantitative.
Qualitative observations describe properties or occurrences in ways that do not rely on numbers.
Quantitative observations are measurements, which by definition consist of both a number and a unit
FORMULATE A HYPOTHESIS
Scientists usually begin to investigate by forming a hypothesis that may not be correct, but it translates a scientist’s understanding of the system being studied into a form that can be tested.
DESIGN AND PERFORM EXPERIMENTS
After the design and execution of experimental hypotheses are formed, scientists conduct experiments to test their effectiveness. Experiments are systematic observations or measurements, preferably under controlled conditions—i.e.—under conditions of change in a single variable.
ACCEPT OR MODIFY THE HYPOTHESIS
Experiments that accept or modify assumptions properly designed and executed enable scientists to determine whether the original assumptions are valid. If the hypothesis is valid, the scientist can proceed to the next step.
DEVELOPMENT INTO A LAW AND/ OR THEORY
In other cases, experiments often show that the assumption is incorrect, or that it must be modified and require further experiments.
Develop into a legal and/or theoretical more experimental data, then collect and analyze, at which point scientists may begin to believe that the results are reproducible enough (IE, reliable) that it is worth summarizing in a legal, oral or mathematical description of a phenomenon, allowing for general predictions.
The law just says what happened; it doesn’t solve the question of why. While the law only explains what happens, the theory tries to explain why nature behaves as it does.
Unless a major Experimental Error is found, the law is unlikely to change much over time. On the contrary, a theory, as the name suggests, is incomplete and imperfect, evolving over time to explain new facts as they are discovered.