Physical Science Chapter 24 Notes

24-1 Chemical Changes Describing chemical reactions

o Chemical reaction:

Ex: o Reactant:

They Ex:

o Product: They Ex:

o General format:

Conservation of mass o Law of conservation of mass: o Discovered by

o Experiment:

He The product The total mass

Writing Equations o Describing

Ex:

o Chemical equation:

Ex: Go over Table 1 on page 740

Unit managers o Coefficient:

Where are coefficients found? Represent

Ex: Show There must

The arrow

Similar to math

24-2 Chemical Equations Balanced chemical equation: Steps to balance equations

1. If necessary,

NEVER ONLY

2. Starting with the first element,

Use multiplication Use addition

3. Using multiplication 4. Put

When blanks are provided for you,

Otherwise,

5. Repeat 6. Double check your work 7. Make sure

24-3 Classifying Chemical Reactions Synthesis reaction:

o General formula: o Ex:

Decomposition reaction:

o General formula: o Ex:

Single displacement:

o A metal o General formula: o Ex: o The activity series of element:

Not all single displacement reactions will happen It will only happen

Double displacement:

o General formula: o Ex: o This happens o Precipitate:

It 24-4 Chemical Reactions and Energy Chemical reactions – energy exchanges

o All chemical reactions o Chemical bonds

It takes Energy is If a reaction takes more energy to break the

chemical bonds than it releases when new bonds are formed, will it release energy or absorb energy?

If a reaction releases more energy when new bonds are formed than it takes to break the chemical bonds in the reactants, will it release energy or absorb energy?

More energy out o Exergonic reaction:

How does this relate to the bonds? Ex:

o Exothermic reaction:

How is this different from an exergonic reaction? Ex:

More energy in o Endergonic reaction:

How does this relate to the bonds? Ex:

o Endothermic reaction: Ex: This can also

o Catalyst

These are These

They

o Inhibitor:

Ex: o Sometimes

Ex:

Browning The