Balancing equations

What are the five types of chemical reactions?

Synthesis, decomposition, combustion, singular replacement, and double replacement

Synthesis

A+B —> AB

Decomposition

AB —> A+B

Combustion

C x Hy + O₂ —> CO₂ + H₂O

Single replacement

A + BC —> B + AC

Double replacement

AB + CD —> AD + BC

Indicators of a chemical change

-change in color

-production of gas

-formation or precipitate

-temperature

-light

Qualitative

Observation that’s a color, smell, taste, texture

Quantitative

Observation based on numbers

What comes before the —>

Reactants

What comes after the —>

Products

A chemical equation is balanced when…

The number of atoms of each element is the same in both reactants and products

In a chemical equation the coefficients…

Appear before the chemical formulas

What is wrong with the following model of a chemical reaction?

One box contains more atoms than the other

What is a chemical reaction?

When one or more new compounds are formed by rearranging atoms

What is a chemical equation?

It is a shorthand notation for illustrating a chemical reaction

The reactants shown schematically below represent iron oxide, Fe₂O₃ and carbon monoxide, CO. Which of the following is the correct full balance chemical equation for what is depicted?

A) Fe₂O₃ + 3 CO —> 2 Fe + 3 CO₂

B) Fe₂O₃ + 3 CO —> 3 FeO + 2 C

C) Fe₂O₃ + 3 CO —> 3 FeO₂ + 2 C

D) Fe₂O₃ + 3 CO —> 2 Fe + 3 C₂ O

A) Fe₂O₃ + 3 CO —> 2 Fe + 3 CO₂

What is a physical change?

State of matter changes, but the molecular structure states the same