Chapter 6: Chemical Reactions an Introduction:
Chemical Reactions:
Main Concepts:
*A chemical reaction often gives a visual sign. For example, steel changes from a smooth, shiny material to a reddish-brown, flaky substance when it rusts. Hair changes color when it is bleached. Solid nylon is formed when two particular liquid solutions are brought into contact.
*Chemical reactions often give of a visual clue such as change in color, solid forms change, bubbles are produced, a flame occurs, and so on.
*Sometimes the only signal that a reaction is occurring is a change in temperature as heat is produced or absorbed.
*A chemical reaction often gives a visual sign. For example, steel changes from a smooth, shiny material to a reddish-brown, flaky substance when it rusts. Hair changes color when it is bleached. Solid nylon is formed when two particular liquid solutions are brought into contact.
*Chemical reactions often give of a visual clue such as change in color, solid forms change, bubbles are produced, a flame occurs, and so on.
*Sometimes the only signal that a reaction is occurring is a change in temperature as heat is produced or absorbed.
Chemical Equations:
Main Concepts:
*Chemical change always involves a rearrangement of the ways in which atoms are grouped.
*For example, when the methane, CH4, in natural gas combines with Oxygen, O2, in the air and burns, carbon dioxide, CO2, and water, H2O, are formed. A chemical change such as this is called a chemical reaction.
*Chemical reactions are represented by chemical equations. In a chemical reaction, the reactants are present in the left side of the equation and the products are on the right side of the equation.
*It is important to recognize that in a chemical reaction, atoms are neither created nor destroyed.
Main Concepts:
*Chemical change always involves a rearrangement of the ways in which atoms are grouped.
*For example, when the methane, CH4, in natural gas combines with Oxygen, O2, in the air and burns, carbon dioxide, CO2, and water, H2O, are formed. A chemical change such as this is called a chemical reaction.
*Chemical reactions are represented by chemical equations. In a chemical reaction, the reactants are present in the left side of the equation and the products are on the right side of the equation.
*It is important to recognize that in a chemical reaction, atoms are neither created nor destroyed.
Balancing Chemical Equations:
Main Concepts:
*An unbalanced chemical equation is not an accurate presentation of the reaction that occurs. The principle that lies at the heart of the balancing process is that atoms are conserved in the chemical reaction.
*Atoms are neither created nor destroyed they are just grouped differently.
*The same number is found upon the products as it is among the reactants.
*The identities of the compounds must never be changed in balancing a chemical equation.
*Most chemical equations can be balanced by trial and error.
Activity:
http://quizlet.com/2854988/balancing-chemical-equations-flash-cards/
*This activity is a Quizlet to help practice recognizing when an equation is balanced or not.
Website:
http://www.webqc.org/balance.php
*This is a website to help show how to balance an equation and practice it at the same time.
Video:
http://www.youtube.com/watch?v=UGf60kq_ZDI
*This video explains how to balance equations by showing step by step how to balance out each sides of the chemical equation.
Main Concepts:
*An unbalanced chemical equation is not an accurate presentation of the reaction that occurs. The principle that lies at the heart of the balancing process is that atoms are conserved in the chemical reaction.
*Atoms are neither created nor destroyed they are just grouped differently.
*The same number is found upon the products as it is among the reactants.
*The identities of the compounds must never be changed in balancing a chemical equation.
*Most chemical equations can be balanced by trial and error.
Activity:
http://quizlet.com/2854988/balancing-chemical-equations-flash-cards/
*This activity is a Quizlet to help practice recognizing when an equation is balanced or not.
Website:
http://www.webqc.org/balance.php
*This is a website to help show how to balance an equation and practice it at the same time.
Video:
http://www.youtube.com/watch?v=UGf60kq_ZDI
*This video explains how to balance equations by showing step by step how to balance out each sides of the chemical equation.
Calculation:
Balance the following equation:
NaOH + H2SO4 ---> Na2SO4 + H2O C3 H8 O2 -----> H2O + CO2
the answer and explanation are found below: the answer and explanation are found below:
Balance the following equation:
NaOH + H2SO4 ---> Na2SO4 + H2O C3 H8 O2 -----> H2O + CO2
the answer and explanation are found below: the answer and explanation are found below: