Chem Definitions

Product

a new substance formed at the end of a chemical reaction

Reactant

the substances that interact to create a chemical change

Chemical Equation

representation of a chemical reaction in the form of symbols and chemical formulas

Balanced Equation

when the same number of atoms are present on both sides of an equation.

Skeleton Equation

a basic, unbalanced chemical equation with no coefficients

Exothermic reaction

chemical reactions which release energy from the chemicals into the surroundings

Endothermic reaction

a chemical process that absorbs heat from its surroundings to proceed, causing the immediate environment to feel colder

Law of conservation of matter/mass

matter cannot be created or destroyed

Coefficients

the whole number placed in front of a chemical formula in a chemical equation to indicate the number of molecules or atoms involved in a reaction

What four things identify chemical reactions?

color change, production of a gas, formation of a precipitate, and energy transfer

Identify the five types of chemical reactions.

Synthesis, decomposition, single replacement, double displacement, combustion.

What does the symbol (s) mean?

solid state

What does the symbol (l) mean?

liquid state

What does the symbol (aq) mean?

aqueous state

What does the symbol (g) mean?

gaseous state

What is the difference between a single and double replacement?

single-replacement reaction replaces one element for another in a compound. a double-replacement reaction exchanges the cations (or the anions) of two ionic compounds

What are the seven diatomic molecules found in nature?

Hydrogen, Nitrogen, Fluorine, Oxygen, Iodine, Chlorine, Bromine (HNFOICB)

When you are balancing an equation what are you balancing on each side?

the total number of atoms

Explain what a combustion reaction is, what is needed and what is formed?

exothermic redox chemical reaction. fuel, oxygen and heat, releases / creates heat and/or light

If a substance during a reaction changes its phase from solid → liquid or liquid → gas does this indicate a chemical change?

No, it’s a physical change, not a chemical change