Chemistry Chapter 8 Chemical Equations •

Indications of a Chemical Reaction

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2)

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1)2)

3)

C. Johannesson

Law of Conservation of Mass● mass is neither created nor destroyed in a chemical

reaction

4 H2 O

4 H2 O

4 g 32 g

36 g

● total mass stays the same

● atoms can only rearrange

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Symbols Used in Chemical Equations⟶ yields(s) solid(l) liquid(aq) aqueous(g) gasΔ reactants heated

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Significance of a Chemical Equation

1)

2)

3)

Writing Equations

● Identify the substances involved.● Use symbols to show:

2H2(g) + O2(g) → 2H2O(g)

∙How many? - coefficient∙Of what? - chemical formula∙ In what state? - physical state

● Remember the diatomic elements.

C. Johannesson

Writing EquationsTwo atoms of aluminum react with three units of

aqueous copper(II) chloride to produce three atoms of copper and two units of aqueous aluminum chloride.

• How many?• Of what?• In what state?

Al 2 (s) + 3CuCl2(aq) → 3Cu(s) + 2AlCl3(aq)

Rules for Balancing Chemical Equations

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2)

3)

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4)

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Types of Chemical Reactions

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Types of Chemical Reactions

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Types of Chemical Reactions

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Types of Chemical Reactions

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Types of Chemical Reactions

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