Conservation of Mass and Chemical Equations/Reactions Flashcards
What does a chemical change involve?
The reaction of a substance to produce a new substance.
True or False: A chemical change always involves the conversion of substances, called reactants, into other substances, called products.
True
Reactant Definition
A pure substance that undergoes a chemical change.
Product Definition
A pure substance that is formed in a chemical change; the properties of the product are different from the properties of the reactants.
True or False: The properties of the products are different from the properties of the reactants, even though the products have the same atoms as the reactants.
True
In a chemical reaction, what is conserved (they are neither created nor destroyed)?
Atoms
The atoms, however, are rearranged to form what?
New substances
True or False: A chemical reaction is one or more chemical changes that occur at the same time.
True
Chemical Reaction Definition
A process in which new substances with new properties are formed.
What does the Law of Conservation of Mass state?
In a chemical reaction, the total mass of the products is always the same as the total mass of the reactants.
What is used to represent a chemical reaction?
A chemical equation
Chemical Equation Definition
A representation of what happens to the reactants and products during a chemical change.
What are the three forms of chemical equations?
-A word equation
-A skeleton equation
-A balanced chemical equation
Explain what a word equation includes
-The name of each reactant is written to the left of an arrow;
-The name of each product is written to the right of the arrow
-A plus sign on the reactant side means “reacts with”
- A plus sign on the product side means “and”;
-The arrow stands for “yields or reacts to produce.”
Explain what a skeleton equation includes
-Shows the reactants and products of a reaction, but does not provide information about the chemical composition of the substances;
-Replacing the words with chemical formulas produces a skeleton equation.
Explain what a balanced chemical equation includes
-Demonstrates the law of conservation of mass, which requires the same number of atoms of each element to appear on both sides of a chemical equation;
-A coefficient is a number that is placed in front of a chemical formula in a balanced equation to show how many units of the substance are involved in the reaction.
Coefficient Definition
A number that is placed in front of a chemical formula in a balanced chemical equation.
Work on Worksheets under “Chemistry Unit Test Review” to practice the Law of Conservation of Mass, Balancing Chemical Equations and Textbook Questions 1-3 and 6-8 on page 158
Depending on Comfort Level
Electronegativity Definition
A measure of the tendency of an atom to attract a shared pair of electrons.
The measure of electronegativity is affected by the atomic number of the atom as well as the relative distance between the _______ and the _________ _______
Nucleus; Valence Shell
True or False: As the atomic number increases, so does the distance between the nucleus and the valence shell.
True
A large electronegativity difference between two atoms will lead to an ________ bond.
Ionic
A small electronegativity difference between two atoms will lead to a ___________ bond.
Covalent
